DoD 2019.B STTR Solicitation

TECHNOLOGY AREA(S): Weapons 

OBJECTIVE: OBJECTIVE: Design, develop, prototype and demonstrate a selection of Freeform Optics that allow for the reduction of lens elements required to reproduce color-corrected imagery. Evolve the technology for manufacturability and survivability in a military environment. This technology will benefit Squad, Crew Served and Sniper fire control systems by reducing the size, weight and complexity of Fire Control devices and enablers. 

DESCRIPTION: The necessity for snipers, soldiers, and crew served weapons operators to rapidly and accurately detect targets on the battlefield is a capability that is of high interest to the department of defense, across all agencies. Traditional optics are radially symmetric while freeform optics can be non-radially symmetric. The increased flexibility of freeform optics allow for potentially revolutionary optical designs. Previously freeform optics were not really practical due to manufacturing limitations. Additive manufacturing technologies such as three dimensional printing are making an entire new generation of optical components and designs possible. For example, an Alvarez lens system is capable of providing a continuously variable focal length with a compact size. A Freeform optical element that is able to precisely focus light at different wavelengths will reduce the number of optical components required in a weapon mounted fire control sighting system, greatly reducing the size and weight of the system. The threshold wavelength range is 390nm to 700nm (Human Visible Spectrum). The objective wavelength range is from 390nm to 1600nm. The intent is for the contractor to determine what level of achromaticity is achievable across the spectrum of visible light using this technology. The Freeform lens design and manufacturability technology developed under this effort will result in cost and weight savings across all branches of the armed forces. The transition of this technology to industry will reduce the size, weight & complexity of optical systems by reducing the number of lenses required in nearly every precision optical system. 

PHASE I: Identify materials, methods and models for producing Freeform Optics, in particular solutions that use 3d printed polymeric materials, however, it is not the intent of the author to specify how the optics are to be fabricated. Optical properties shall be modeled, and performance quantified. Small-scale proof-of-concept samples shall be produced with identified materials and methods. Any software utilized and literature addressed shall be identified by the contractor. Contractor shall clearly state in the proposal and final report how the phenomenology provides the unique capability for achieving the design goals. Freeform optic design software will be used to define how a fielded small arms fire control system could benefit from a Freeform design. Efficiencies of at least 10% shall be demonstrated through modeling of the optical system design complexity (the number of optical elements), the size of the optical system, and the commensurate savings in weight shall all be described in the final report. 

PHASE II: Develop prototype Freeform optical units. Prototype shall be F/7 or faster, with a half field of view no less than 5 degrees. Prototype shall be optimized for a minimum of three (3) visible wavelengths (486nm, 587nm, 656nm). A variable magnification system based on Alvarez lenses or another freeform optic is of considerable interest. The contractor shall perform modeling and simulation that quantifies the optical performance of the prototype (Spot Diagrams [Both Monochromatic & Polychromatic], Ray Fans, MTF [Modulation Transfer Function], Distortion, and Field Curvature). A prototype shall be fabricated and delivered to the Government. Testing shall be conducted on the prototype to verify its actual performance versus modeled expectations. The Government will keep at least one prototype. Any software utilized and literature addressed shall be identified by the contractor. Contractor shall clearly state in the proposal and final report how the phenomenology provides the unique capability for achieving the design goals. Efficiencies of at least 20% shall be demonstrated through modeling of the optical system design complexity (the number of optical elements), the size of the optical system, and the commensurate savings in weight shall all be described in the final report. Technology Readiness Level (TRL): 3 

PHASE III: Optimize the physical properties for military applications. Prototype a rifle mounted fire control sight using this technology that demonstrates the benefits in size and weight over currently fielded systems. Replace conventional optics with the design in a sight that represents the optical performance of a fielded military small arms sighting system. Test and report the results of the optical metrology/performance and weight savings. Create a partnership with industry to commercialize the technology and improve the manufacturability. The prototype will be TRL 4 at the end of phase III. 

REFERENCES: 

1: Freeform: S. Barbero, J. Rubinstein, J. Opt 13 (2011) 125705

2:  A. Moehl et al., SPIE vol 10690, 1069017 (2018).

3:  https://phys.org/news/2017-08-freeform-optical-device-smaller-package.html#nRlv

4:  https://phys.org/news/2018-05-method-guesswork-lenses-freeform.html

5:  http://www.nature.com/articles/s41467-018-04186-9

6:  https://phys.org/news/2015-11-telescope-mirrors.html

7:  https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10690/2313114/Ready-to-use-a-multi-focal-system-based-on-Alvarez/10.1117/12.2313114.full?SSO=1

KEYWORDS: Conformal Optics 

TECHNOLOGY AREA(S): Sensors 

OBJECTIVE: Develop and demonstrate a universal navigation solution manager that provides the best possible navigation solution without human intervention using conventional and alternative navigation sensors in an environment where some or all of those sensors might be compromised, contested, degraded, or denied. 

DESCRIPTION: Increased dependence on Global Positioning System (GPS) has driven the need for alternative navigation solutions in using these systems for critical operations where precise system performance is desired and GPS might be compromised, contested, degraded, or denied. The navigation accuracy and availability of conventional and alternative navigation solutions provided in such a compromised, contested, degraded, or denied environment have the potential to vary depending on the challenges presented by the environment. In addition to accuracy and availability, one must also consider the integrity of the sensed information such that compromised data and/or data estimates that exceed specified limits are excluded from the final navigation solution [1]. Furthermore, the accuracy, availability, and integrity of conventional and alternative navigation information sources may change during the duration of the mission and may depend on factors such as flight dynamics, mission status, sensor parameters, location, system health, etc. The objective is to develop an innovative solution analogous to that of GPS Receiver Autonomous Integrity Monitoring (RAIM) [2] that is capable of identifying and monitoring the accuracy, availability, and integrity of conventional and alternative navigation sources for the duration of the mission and ingesting them into a navigation solution accordingly to provide the best possible navigation solution without the intervention of a human. In advancing alternative navigation technologies applicable to Precision, Navigation, and Timing (PNT), this effort is a key enabler for precision engagements in compromised, contested, degraded, or denied environments in the Army Modernization Priorities for Long Range Precision Fires. Addressing the technical issue of computing the best navigation solution using conventional and/or alternative methods without human intervention will allow for performance improvements in compromised, contested, degraded, or denied environments. By advancing alternative navigation solutions applicable to Army mission scenarios, this effort is an enabler for extended range for systems in the Army Modernization Priorities for Long Range Precision Fires. 

PHASE I: Develop, test, and validate a universal navigation solution manager that demonstrates the capability to provide the best navigation solution by autonomously adjudicating the accuracy, availability, and integrity of conventional and alternative navigation sensors in compromised, contested, degraded, or denied environments. Further define the complete proof-of-concept universal navigation solution manager that will be developed in Phase II. 

PHASE II: Develop, test, and validate a universal navigation solution manager that demonstrates the capability to provide the best navigation solution by autonomously adjudicating the accuracy, availability, and integrity of conventional and alternative navigation sensors in compromised, contested, degraded, or denied environments. The complete proof-of-concept universal navigation solution manager will be delivered to AMRDEC at the end of Phase II. In the event that DoD Components identify topics that will involve classified work in Phase II, companies invited to submit a proposal must have or be able to obtain the proper facility and personnel clearances in order to perform Phase II work. International Traffic in Army Regulation (ITAR) control may be required. Contract Security Classification Specifications, DD Form 254, may be required. 

PHASE III: Advance the universal solution manager developed in Phase II to a marketable product addressing the size, weight, power, cost, and operational environment of military and commercial systems. Precision operation in contested, degraded, or denied environments is important to many missile applications. The ability to autonomously provide the best possible navigation solution in compromised, contested, degraded, or denied environments would be advantageous to many Army systems including current and future systems within Long Range Precision Fires. This technology has the potential to find uses in both military and commercial applications. Commercial applications could include emergency personnel or civilian operations where precision is required such as in urban canyons, mining and tunneling, and indoor environments where conventional and/or alternative navigation sensors have the potential to be compromised, contested, degraded, or denied. 

REFERENCES: 

1: Federal Radionavigation Plan. Technical Report DOT-VNTSC-RITA-05-12/DoD-4650.5, Springfield, VA: Joint Publication by US Departments of Defense, Homeland Security, and Transportation, December 2005.

2:  R. G. Brown. Receiver autonomous integrity monitoring. Global Positioning System: Theory and Applications, II(143-165), 1993.

3:  M. A. Sturza. Navigation system integrity using redundant measurements. Journal of the Institute of Navigation, 35(4), Winter 1988-1989.

4:  Encyclopedia of Polymer Science and Technology, 3rd edition, Wiley, 2007.

5:  S. Moafipoor. Updating the navigation parameters by direct feedback from the image sensor in a multi-sensor system. In Proceedings of the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2006), 2006.

6:  Y. C. Lee. Navigation system integrity using redundant measurements. In Proceedings of the 17th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2004), 2004.

7:  Craig D. Larson, John Raquet, and Michael J. Veth. Developing a framework for image-based integrity. In Proceedings of ION GNSS 2009, pages 778-789, September 2009.

8:  J. L. Farrell and F. van Grass. Statistical validation for GPS integrity test. Journal of the Institute of Navigation, 39(2), 1992.

9:  Larson, C. An Integrity Framework for Image-Based Navigation Systems. Ph.D. Thesis, Air Force Institute of Technology, Dayton, OH, USA, 2010.

KEYWORDS: Autonomous, Integrity, Accuracy, Availability, GPS Denied, Alternative Navigation, Precision, Environment 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Develop a method for the uniform dispersion and alignment of short fiber reinforcement in highly loaded composite materials. 

DESCRIPTION: There is an on-going effort to reduce the weight of Army vehicles to increase combat effectiveness, improve fuel efficiency and reduce the burdens associated with transporting fuel to the battlefield. Currently, there are many fielded Army vehicle parts that are made of aluminum or other metals that could potentially be replaced by lighter and stronger fiber composite materials. The anisotropic nature of the fiber reinforcements often requires the fibers to be highly aligned to obtain advantageous material properties. However, this imposes restrictions on the part geometries due to the need to preserve the continuity of long or continuous fibers. Strong curvatures or sharp angles would cause the fiber reinforcement to break, compromising mechanical properties. A method of addressing this problem is to produce prepregs of highly aligned (>90% of fibers within 5º of the same orientation), short (<5 mm), discontinuous fibers with high aspect ratios (i.e., fiber length divided by fiber diameter), and high fiber volume fractions (>45%). This strategy has two advantages: (1) theoretical models [1, 2] have shown that high alignment with high aspect ratios (approaching 1000) should produce materials that have material properties that approach those of their continuous counterparts and (2) the short fiber material should be readily formable (e.g., it could be stamp formed or compression molded in a manner similar to that of aluminum) due to its discontinuous nature. Despite the central importance of formability while maintaining properties, there is currently no commercially available method for achieving the high precision short fiber alignment mentioned above. There are at least two reasons for this. The first reason is the difficulty in creating a uniform dispersion of short fiber reinforcement in a resin or other fluid media (e.g., air, water) used for alignment. It is extremely difficult to prevent clumping or agglomeration among the short fibers in highly loaded resins due to the electrostatic interactions and dispersion forces that attract fibers to each other, and surface energy mismatches between the reinforcement and the dispersion media that prevent full wetting of the fibers. In addition to compromising the alignment necessary to attain the desired material properties, fiber agglomerates and clumps can impair filling of the resin, creating processing defects in the composite parts. A second reason is the challenge associated with uniformly aligning well dispersed short fibers in a consistent and reproducible manner. Some alignment techniques have shown promise, but they have suffered from the following drawbacks: (i) low fiber volume fractions, (ii) insufficient alignment, or (iii) long overall fiber lengths, which prevented them from achieving materials with properties that approach those of similar continuous materials with better formability. Some of these challenges are themselves associated with the dispersion problems mentioned above. Recently, it was demonstrated that specific patterns or alignments of particles in a fluid can be created through the use of arranged ultrasonic transducers [3, 4]. This was accomplished by developing a sufficient mathematical understanding of the forces generated from ultrasonic interactions that the resulting particle patterns could be predicted. Other researchers have had success in employing electromagnetic fields to accomplish similar controlled alignments (5). Given that it has been established that it is possible to create dispersed and organized patterns using external fields, it should be possible to develop a methodology of creating well-dispersed and highly aligned composites via chemical, acoustic, electromagnetic, or mechanical methods. A method of consistently creating uniform well dispersed and oriented short fiber reinforcement in highly loaded composite materials would not only enable the development of more flexible and inexpensive composite fabrication 

PHASE I: The offeror(s) shall develop a technique to (1) consistently disperse a short fiber (<5mm) reinforcement (e.g. carbon, or glass) in a medium without clumping or agglomeration and use this dispersion to (2) produce a highly aligned (>80% of fibers within 15º of the same direction) in a highly loaded (>30 vol% fiber) thermoplastic or thermosetting matrix (e.g., Nylon 6 or an epoxy resin). Offeror(s) should take care to address or counter the electrostatic interactions between fibers and surface tensions that promote agglomeration. Potential solutions for obtaining good dispersion include, but are not limited to, chemical modification of the fiber and matrix, ultrasonic dispersion, or utilization of EM interactions for dispersion. Potential solutions for alignment include, but are not limited to, fluid flow, (di)electrophoresis, and pneumatic techniques. The goal of phase I is to demonstrate an ability to consistently produce a 30vol% or higher fiber loaded composite sheet with a uniform alignment of short fiber reinforcement. The parts produced by said method should be a minimum of 0.5 mm thick and of sufficient lateral dimensions for a simple tensile test in the fiber direction. Adequate dispersion and alignment of the fibers should be confirmed via microscopic or non-destructive evaluation. Samples shall be provided to Army researchers for independent testing and validation. For Phase II to be awarded, the offers should also be able to articulate a technically viable path for the dispersion and alignment methods to be employed in a flexible composite manufacturing process such as stamp forming or compression molding. 

PHASE II: The offeror(s) shall expand the method in phase I to the development of 45vol% or higher short fiber composites with highly aligned fibers. Highly aligned is defined as 94% of the fiber reinforcement deviating by a maximum of 10° in alignment. The goal of Phase II is to demonstrate the methodology by producing two example parts. One example part is at least 1 mm thick having an angle feature that is >85º and the other is at least 1 mm thick and has a hemispherically shaped feature with a radius of about 2 inches. The offeror(s) shall measure the tensile modulus, tensile strength and short beam shear strength of flat plates of the produced material in a manner consistent with ASTM Standard D3039 and demonstrate variance of no greater than 10% in a set of ten samples. Offeror(s) shall provide additional example parts and test specimens to Army researchers for independent testing and validation. 

PHASE III: The offeror will adapt the dispersion methodology to as many fiber/matrix systems as possible, and develop commercial processes that employ the dispersion/alignment solution for the production of commercial composite parts. The offeror will begin to offer high fiber loaded short fiber composite parts for use in military ground vehicles, military autonomous vehicle, military rotorcraft, and commercial applications in automotive, aerospace, and robotics. 

REFERENCES: 

1: Fukuda, H. and T.-W. Chou, A probabilistic theory of the strength of short-fibre composites with variable fibre length and orientation. Journal of Materials Science, 1982. 17(4): p. 1003-1011.

2:  Lauke, B. and S.-Y. Fu, Strength anisotropy of misaligned short-fibre-reinforced polymers. Composites Science and Technology, 1999. 59(5): p. 699-708.

3:  Prisbrey, M

4:  Greenhall, J

5:  Vasquez, F

6:  and Raeymaekers, B, Ultrasound directed self-assembly of three-dimensional user-specified patterns of particles in a fluid medium. Journal of Applied Physics, 2017. 121: p. 014302

7:  Greenhall, J

8:  Homel, L

9:  and Raeymaekers, B, Ultrasound directed self-assembly processing of nanocomposite materials with ultra-high carbon nanotube weight fraction. Journal of Composite Materials, 2018.

10:  Ma, W-T

11:  Kumar, S

12:  Hsu, C-T

13:  Shih, C-M

14:  Tsai, S-W

15:  Yang, C-C

16:  Liu, Y-Y

17:  and Lue, S-J, Magnetic field-assisted alignment of graphene oxide nanosheets in a polymer matrix to enhance ionic conduction. Journal of Membrane Science, 2018. 563, p. 259-269

KEYWORDS: Composites, Manufacturing Processes, Short Fiber, Dispersion, Fabrication 

TECHNOLOGY AREA(S): Sensors 

OBJECTIVE: To develop high current, high brightness and long lifetime electron amplifiers based on diamond cathodes. 

DESCRIPTION: Stable and efficient electron emitters are critical for a wide range of applications such as high power vacuum electronic microwave/millimeter-wave/terahertz power amplifiers, coherent x-ray sources, electron diffraction and microscopy, electron-beam lithography, flat panel displays, and thermionic energy conversion (TEC) through thermal electron emission for renewable energy generation. Traditional thermionic electron sources operate at cathode temperatures over 1000o to produce appreciable electron emission. Such high temperature have serious consequences in terms of lifetime and reliability. As an electron emitter, diamond offers several advantages over conventional electron emitters. These advantages include a wide bandgap, large breakdown field, high electron mobilities, and high thermal conductivity. Its ability to control electron affinity through surface termination and doping is also extremely important for electron emission. Negative electron affinity (NEA) has been demonstrated through hydrogen termination of the diamond surface. This has resulted in superb electron emissivity even at room temperature. Recent advances of diamond thin film growth based on techniques such as chemical vapor deposition and thermodynamic growth under high-pressure high-temperature have resulted in commercially available large-size, single-crystal, and high-purity synthetic diamond substrates. Furthermore, post growth processing techniques such as surface polishing and atomic layer etching have also significantly reduced surface roughness of these diamond films. All of these new developments now open the door for realizing practical diamond-based applications including efficient and low temperature field-emission electron sources. In a diamond electron amplifier (DEA), electrons are generated as secondary emission from a hydrogen terminated surface of a diamond film after excitation by a primary electron beam. It has demonstrated the ability to amplify an electron beam current by several orders of magnitude while at the same time yielding high current and high electron beam quality with ultralow emittance and energy spread while maintaining relative low cathode temperatures. All of these are desirable characteristics for the aforementioned applications. However, key scientific and technical challenges still need to be addressed for DEAs to realize their full potential. Issues such as hydrogen desorption under high current and elevated temperature and DC shielding by surface charge build-up due to surface dangling bonds and impurities have been observed and resulted in reduced electron emission efficiency. The origin of these surface degradation processes need to be investigated and eventually compensated in order to recover the reduced emission efficiency. New surface processing techniques for surface termination with molecules other than hydrogen and incorporating dopants into diamond can also be investigated and developed to achieve higher NEA and further improve electron emission efficiency. The goal of this topic is to investigate electron emission process from diamond, develop new surface processing techniques for diamond to improve electron emission efficiency, and create DEA prototypes which incorporate these new techniques to achieve high current, high brightness and long lifetime operation. 

PHASE I: During the Phase I effort, a numerical model and design methodology for diamond electron amplifiers (DEAs) will be developed. A prototype DEA will be designed and tested to verify the model and design methodology. Technical risks will be identified and plans for minimizing these risks will be devised. The prototype devices should have the following specifications: electron energy of 10 KeV, average current of 0.5 µA, bunch charge of 200 pC, diamond amplifier gain of ~200. New techniques for surface termination and doping to improve emission from diamond and related materials will be investigated. 

PHASE II: A prototype diamond electron amplifier (DEA) will be designed based on the numerical model and design methodology developed in Phase I. The prototype device will be built, assembled, and tested. Target specifications for the Phase II design are as follows: electron energy of 100 keV, average current of 0.3 mA, bunch repetition frequency of 3 MHz, thermal emittance of 0.2 µm, maximum peak current of 100 mA, diamond amplifier gain of >200 and a lifetime of at least one year. Technical risks will be identified and plans for minimizing these risks will be devised. New techniques for surface termination and doping to improve emission from diamond and related materials will be investigated, and incorporation of these new techniques into the Phase II prototype will be explored. 

PHASE III: Diamond electron amplifiers (DEAs) would be highly beneficial for applications requiring high current, high brightness and stable electron beams, e.g., high power, high frequency vacuum electronic power amplifiers for radar and directed energy applications, coherent x-ray generation, and thermionic energy conversion (TEC) through thermal electron emission for renewable energy generation. Phase III effort will explore opportunities for integrating DEAs with suitable electron beam parameters into these systems for improved performance in both defense and commercial sectors. An example of a potential Phase III product demonstration will be a high power microwave source such as a traveling wave tube with an integrated DEA cathode. The targeted frequency and power level should be in the range of X-band (8-12 GHz) and ~10s-100 KW which would be suitable for insertion into existing radar and/or directed energy systems. 

REFERENCES: 

1: J.Y. Tsao, et al., "Ultra-wide-Bandgap Semiconductors: Research Opportunities and Challenges," Adv. Electron. Mater. 4, 1600501 (2018).

2:  X. Chang, et al., "Electron beam emission from a diamond-amplifier cathode," Phys. Rev. Lett. 105, 164801 (2010).

3:  W.F. Paxton, et al., "Thermionic Emission from Diamond Films in Molecular Hydrogen Environments," Front. Mech. Eng. 3, 18 (2017)

4:  M.C. James, et al., "Negative electron affinity from aluminium on the diamond (1 0 0) surface: a theoretical study," J. Phys: Condens. Matter 30, 235002 (2018)

5:  K.M. O'Donnell, et al., "Extremely high negative electron affinity of diamond via magnesium adsorption," Phys. Rev. B 92, 035303 (2015)

KEYWORDS: Ultrawide-bandgap Semiconductors, Diamond Thin Films, Electron Sources, Negative Electron Affinity, Hydrogen Termination, Field Emission, Secondary Electron Emission, Diamond Electron Amplifiers 

TECHNOLOGY AREA(S): Sensors 

OBJECTIVE: To develop high-speed mid-infrared free-space laser communications devices at wavelengths significantly longer than current short wave infrared commercially available systems. Specifically, to develop Watt-level mid-wave and long-wave infrared high-speed semiconductor lasers for transmitters and related high-speed photodetectors for receivers. 

DESCRIPTION: Mid-infrared photonics components such as quantum cascade lasers (QCLs) and p-n junction based photodetectors are poised to make an impact on free-space laser communications. Such transmitters and receivers could produce high power beams from very compact packages. Speeds of multi-Gbps data rates should clearly be achievable with potential to go even faster than bipolar lasers thru use of unipolar QCLs due to faster carrier transport of purely electron based devices. However, few advances have occurred to push such approaches beyond the initial investigation phase [1]. More recent advances in reliable, Watt-level output power QCLs show the readiness for further pursuit of free-space laser communications based upon these devices [2]. Other lasers based on antimonide semiconductors have also progressed to Watt-level output powers needed for significant link distances [3]. Mid-infrared photodetectors have also advanced in various materials showing promise to be developed into high-speed receivers for sensitive, low bit-error-rate (BER) performance [4, 5]. Such laser communications links would have high applicability for military scenarios as well as civilian systems [6] where 1.55 micron components have been dominant. Long-wave infrared (LWIR) wavelengths in the 8-12 micron range, and to a lesser extent mid-wave (or MWIR) wavelengths at 3-5 microns, have clear advantages over such commercial systems due to reduced Rayleigh scattering. However, the receiver signal to noise ratio (SNR) may be strongly influenced by other factors including background infrared radiation sources (manmade or otherwise) that could encourage multi-channel development (both in MWIR and LWIR). This project is aimed at developing both detectors and lasers that could be used in such systems for high-speed laser communications. Military relevance would be found in both primary and alternative communication pathways and commercial relevance is seen for high-speed data communications with extended range operation. 

PHASE I: To develop the epitaxial growth, design and fabrication processes for the lasers and photodetectors needed for high-speed free-space laser communications. The laser should be capable of 1W output power (continuous-wave, room temperature) and modulated at 5 Gb/s or more. MWIR and LWIR wavelength ranges should be considered for multichannel solutions to make robust data communications links. Photodetectors need to meet the specifications to create a low BER and high data rate. Justification should be made whether the very highest detectivity HgCdTe based detectors or needed or more cost effective and sufficient III-V semiconductor based solution has merit. 

PHASE II: To pursue a full device demonstration for high-speed data communications in a laboratory environment. Data rates of at least 5 Gb/s should be achieved for a laser communications link demonstration with studies to show BER performance versus speed. Minimum requirements would be for BER of 1e-12 at 5 Gb/s. Insertion of the devices into bulk optics systems would be sufficient for link demos. Exploration of the limits of the data speed should be made up to 50 Gb/s. Production scale costs of the devices should be studied to show viability for reasonable cost devices at manufacturing volumes. Motivation for phase III follow-on investment should be made evident. 

PHASE III: Pursuit of free-space laser communications links products – transmitters and receivers based upon the laser and photodetector devices developed in phase II. Such products would need to include the packaging of the full transmitter and receivers including the optics, driver circuitry and related software needed to monitor and use the equipment. The range and speed that these products can achieved would need studied in both military and commercial application scenarios. Multi-channel, e.g. multi-wavelength products should be explored to improve BER performance. Wall-plug efficiency of the transmitter and detectivity of the receiver photodetector should be evaluated relevant to the application and costs of the transmitter and receiver. Atmospheric turbulence mitigation systems and experiments would also need to be pursued, particularly for military relevant scenarios. Applications would include networking across a battlefield or environment where RF jamming signals are in use and may involve multi-hop, non-line-of-sight networks for avoiding obstacles, obscurants or for other reasons such as lower signal distortion of certain paths. Other considerations may be incorporation of components into beam steering systems, for agile, moving systems, e.g. UAVs, UGVs, planes, other mobile platforms. 

REFERENCES: 

1: S. Blaser, D. Hofstetter, M. Beck, and J. Faist, "Free-space optical data link using Peltier-cooled quantum cascade laser," Electronics Letters, Vol. 37, No. 12, June 2001.

2:  Y Bai, N Bandyopadhyay, S Tsao, S Slivken, M Razeghi, "Room temperature quantum cascade laser with 27% wall plug efficiency," Applied Physics Letters, Vol. 98, No. 18, 181102, 2011.

3:  T. Hosoda, G. Kipshidze, G. Tsvid, L. Shterengas, G. Belenky, "Type-I GaSb-based laser diodes operating in 3.1-3.3 µm wavelength range," IEEE Photon. Technol. Lett., Vol. 22, 718, 2010.

4:  K. K. Choi, S. C. Allen, J. G. Sun, Y. Wei, K. A. Olver, and R. X. Fu, "Resonant structures for infrared detection," Applied Optics, Vol. 56, Issue 3, pp. B26-B36, 2017.

5:  M. Kopytko, A. Keblowski, P. Madejczyk, et. al., "Optimization of a HOT LWIR HgCdTe Photodiode for Fast Response and High Detectivity in Zero-Bias Operation Mode," J. of Electronic Materials, Vol. 46, No. 10, 2017.

6:  X. Pang, O. Ozolins, R. Schatz, et. al., "Gigabit free-space multi-level signal transmission with a mid-infrared quantum cascade laser operating at room temperature," Optics Letters, Vol. 42, No. 18, Sept. 2017.

KEYWORDS: Mid-infrared, Photonics, Lasers, Photodetector, Free-space Optical Communications 

TECHNOLOGY AREA(S): Ground Sea 

OBJECTIVE: To create a mathematical and numerical framework for the design, analysis, and optimization of performance of mobility system components that are subject to significant fluid-structure interaction effects. 

DESCRIPTION: The intent of this solicitation is to achieve superior accuracy and high-fidelity solutions in computational flow and fluid-structure interaction analysis for com-plex engineering applications, including military and commercial applications, through efficient conforming methods such as Isogeometric Analysis (IGA). Software objectives include extending CAD models to IGA models for high-fidelity computation on supercomputers, doing the required mesh generation automatically or without substantial user effort, and developing a good graphical user interface for conducting simulations and post-processing of results. IGA [1], because of its special higher-order nature, has several very desirable features in multiscale computation of flow and fluid-structure interaction (FSI) problems, including superior spatial and temporal accuracy in the flow solution and more accurate, sometimes exact, representation of the solid surfaces, in-cluding and especially those coming from CAD models. This plays a crucial role in many classes of problems. Compared to classical methods such as the finite differences and finite elements, it performs well even in computations with high-aspect-ratio elements; such elements are inevitable in real-world flow and FSI problems where accurate representation of boundary layers requires very small/thin elements near complex solid surfaces in internal flows and FSI prob-lems where contact between solid surfaces requires meshes in very narrow spaces. Also, for the same level of accuracy, it generally requires fewer un-knowns than classical methods, and so it has larger effective element sizes and therefore the computations can be done accurately with larger time-step sizes, resulting in substantial savings in computing time. Because it shifts the compu-tational burden from the number of unknowns to the number of floating-point operations per unknown, and because it does that without creating any compu-tational disadvantages, it is very suitable for efficient parallel computing. This makes IGA attractive in real-world flow and FSI analysis and is the reason this solicitation seeks to implement it in important mobility applications. IGA-based computation has been applied to FSI problems in turbomachinery [2], tire aerodynamics [3], ship hydrodynamics [4], and gas turbines [5-7]. However, mesh generation with IGA, such as in Nonuniform Rational B-Splines (NURBS) mesh generation, is not as established and straightforward as mesh generation in the classical methods such as the finite differences and finite elements. To make IGA-based flow and FSI computations even more powerful and practical, this solicitation seeks implementations that make the mesh generation more straightforward and automated, similar to current finite difference and finite ele-ment methods. It seeks easier adaptivity of solutions, such as creating thin lay-ers of elements near solid surfaces to accurately represent the boundary layers with less user effort. It seeks more user-friendly and dynamic mesh motion that matches the structure motion and deformation in an FSI computation, automati-cally maintaining the thin layers of elements created near solid surfaces. Basically, extending the CAD models to IGA models in terms of mesh generation, solution adaptivity and FSI mesh motion has to be more automated, embedded in a good graphical user interface (GUI). The product will enable IGA-based computation to play an expanded and significant role in enabling mobility design in military and commercial applications. 

PHASE I: a) Identify the most promising path(s) forward from existing methods and implementations of NURBS mesh generation in real-word mobility applications of interest, such as turbocharger turbines with exhaust manifolds, parachutes, and rotor-stator interactions in adaptive axial-flow or centrifugal turbomachinery with pitching blades/stator vanes. Identify typical applications and regimes of interest, and identify relevant geometries and parameters suitable to demonstrate the feasibility of IGA-enabled solutions. b) Develop and demonstrate the generation of a NURBS mesh made of patches, demonstrate recovery of the original model surfaces, and demonstrate the suitability of the recovered surface for accurate and robust fluid mechanical computations. c) Develop GUI implementation of the method. The focus will be on NURBS meshes. In problems with complex geometries, it may be necessary to use multiple NURBS patches; making that more user-friendly should be one of the GUI features. There should be two options for handling the joints be-tween patches: C0-continuity, or C-1-continuity (probably with discontinuous functions). d) Automate the mesh motion matching the structure motion and deformation in an FSI computation. The motion of the solid surfaces can be represented by using time-dependent NURBS basis functions as one of the possible feature choices in the GUI implementation. e) Implement the foregoing scheme numerically and conduct appropriate proof-of-concept computations. 

PHASE II: a) Expand the computational technique to basis functions other than NURBS, such as T-splines or others. By conducting numerical and automated tests, demonstrate that the selected linear combinations of basis functions optimally reconstruct a variety of surfaces. b) Explore methods for boundary layer refinement such as knot insertion, in-creasing the polynomial order, or particular combinations of the two (i.e., h,p,k refinement). Automate this refinement process. c) Demonstrate utility in a wide set of test mesh generations from CAD models for mobility applications. Use to evaluate the performance of the method and the GUI. d) Port the mesh generation module to parallel computing platforms and optimize performance on those platforms. e) The computational method shall be capable of performing dynamic transient flow simulations as fluid-structure interaction happens in adaptive or morphing structures interacting with fluid flows for both internal and external flows. The computational method shall be verified and validated by conducting required fluid flow experiments using a pitching annular turbomachinery cascade with articulating stator and rotor blade configuration. f) The computational technique will be tested, validated, and implemented as a documented software package that can be shared or marketed. g) Transition the developed methods and software, including documentation, to interested users in academia (e.g. CFD and Mobility Design research groups in the US and Europe), industry, and government (e.g. ARL-VTD, TARDEC) under appropriate licensing agreements. The software package will ultimately be integrated into the CREATE environment at HPCMP or at least be port-able to DoD HPC platform so that DoD and other government agencies and Universities can use the software within HPC environment. 

PHASE III: The uniquely capable analysis and numerical techniques developed under this topic will achieve superior accuracy and high-fidelity solutions in computational flows and fluid-structure interaction analysis involving flexible boundaries. This will in turn enable rapid, high quality solutions in a variety of complex engineering applications, especially those involving high velocity/high pressure flows over deforming elements, such as found in turbines, in highly deformable elements such as MAV rotors, and others. This will therefore make great progress in the design of a wide variety of both military and commercial applications, such as commercial and military aircraft turbines, commercial and military rotorcraft turbines, commercial and military MAV flexible rotors, etc. 

REFERENCES: 

1: [1] T.J.R. Hughes, J.A. Cottrell, and Y. Bazilevs, "Isogeometric analysis: CAD, finite elements, NURBS, exact geometry, and mesh refinement", Computer Methods in Applied Mechanics and Engineering, 194 (2005) 4135-4195.

2:  [2] Y. Otoguro, K. Takizawa, T.E. Tezduyar, K. Nagaoka and S. Mei, "Turbo-charger Turbine and Exhaust Manifold Flow Computation with the Space-Time Variational Multiscale Method and Isogeometric Analysis", Computers & Fluids, published online, 10.1016/j.compfluid.2018.05.019 (May 2018).

3:  [3] T. Kuraishi, K. Takizawa and T.E. Tezduyar, "Space-Time Computational Analysis of Tire Aerodynamics with Actual Geometry, Road Contact and Tire De-formation", Chapter in a special volume to be published by Springer (2018).

4:  [4] I. Akkerman, Y. Bazilevs, D.J. Benson, M.F. Farthing, and C.E. Kees, "Free-Surface Flow and Fluid-Object Interaction Modeling with Emphasis on Ship Hy-drodynamics", Journal of Applied Mechanics, 79 (2012) 010905.

5:  [5] M.-C. Hsu, C. Wang, A.J. Herrema, D. Schillinger, A. Ghoshal, and Y. Ba-zilevs, An interactive geometry modeling and parametric design platform for isogeometric analysis, Computers & Mathematics with Applications, 70 (2015) 1481-1500.

6:  [6] F. Xu, G. Moutsanidis, D. Kamensky, M.-C. Hsu, M. Murugan, A. Ghoshal, and Y. Bazilevs, "Compressible flows on moving domains: Stabilized methods, weakly enforced essential boundary conditions, sliding interfaces, and applica-tion to gas-turbine modeling", Computers and Fluids, 158 (2017) 201-220.

7:  [7] M. Murugan, A. Ghoshal, F. Xu, M.-C. Hsu, Y. Bazilevs, L. Bravo, and K. Kerner, "Analytical study of articulating turbine rotor blade concept for improved off-design performance of gas turbine engines", Journal of Engineering for Gas Turbines and Power 139 (2017) 102601.

8:  [8] Y. Otoguro, K. Takizawa and T.E. Tezduyar, "A General-Purpose NURBS Mesh Generation Method for Complex Geometries", Springer (2018).

KEYWORDS: Isogeometric Analysis, Mobility, Fluid-structure Interaction 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Develop a technique/approach/methodology to deposit known crystalline ferromagnetic or antiferromagnetic insulators on topological materials such as Bi2Se3 at low temperature below 300~400°C. 

DESCRIPTION: Since Topological insulators (TIs) were discovered a decade ago, the understanding of this new physical phenomena progressed rapidly as evidenced in literature growth. However, the technological potential of this interesting new class of materials has not advanced sufficiently for technology realization. The goal of this topic is to address the traditionally weak link between knowledge generation and applied research/engineering to accelerate the pace of new technology development. Among the known TIs, high quality Bi2Se3 in combination with ferromagnetic (FM) and antiferromagnetic (AFM) materials forming a planar heterojunction is expected to provide a unique opportunity to develop energy efficient electronics ranging from low power switching and memory to energy harvesting. A TI channels electrical current through 100% spin polarized surface states ensuring a very highly efficient exchange interaction with adjacent magnetic materials. The resulting spin orbit torque transfer [1] enables magnetic order in an FM or AFM to be switched at much lower energies than can be achieved with conventional heavy metals. Proposed TI-based energy efficient electronics have, however, been hampered because standard approaches to epitaxy of magnetic materials such as molecular beam epitaxy and pulsed laser deposition require sample temperatures above what TIs can survive. Deposition of the TI on the magnetic material is also ill suited for device and circuit patterning and does not surmount the challenge. Because of the excitement and nascent nature of the field of topological materials, alternative methods for building heterostructures with other materials, ranging from mechanical approaches to low temperature chemical techniques have not yet been considered. Such techniques have been established in other electronic materials but have not been applied in the context of topological plus magnetic materials. This STTR topic therefore seeks an innovative technique/approach/methodology for the deposition of known insulating FM or AFM materials on topological materials such as Bi2Se3 (other well investigated TI materials with spin polarized topologically protected electronic surface states are also of interest) at low temperature (e.g. below 300°C) so that the integrity of the underlying TI material is maintained by its own chemical and physical stability. Key aspects to form the heterostructure are (i) the control of the formation of the terminating top atomic layer on the surface of TI materials, (ii) the formation of the first atomic layers of the deposited magnetic material on the TI material, and (iii) sustaining the magnetic order of the magnetic material. Layer by layer deposition preserving the underlying TI quality is highly desired under a set of available parameters such as temperature, pressure, deposited thickness and speed. The created interface/heterostructure, as demonstrated in Ref [1-2], is expected to be characterized by advanced measurement and analysis to determine the interface structure and the electronic and magnetic interactions between the two different materials. Understanding the relationship of the interface characteristics as well as the nature and extent of the electronic/magnetic interactions is expected for iterated tunings and optimizations. Alternative techniques to create structurally well-defined and atomically regular interfaces between magnetic materials (as an over-layer) and high quality TI materials (as a substrate) will be considered. 

PHASE I: Demonstrate low temperature deposition or alternative method for interfacing magnetic materials on dichalcogenide topological insulators. Theoretical and computational efforts may also be included. The results of Phase I should demonstrate a path forward toward optimized materials, interfaces and control over the interface exchange interaction. 

PHASE II: Demonstrate low temperature juxtaposition (deposition or other technique) of high quality magnetic insulators on high quality topological insulators. The “high quality” metric is defined by a heterostructure that retains the performance characteristics of the topological insulator and is suitable for control of the magnetic anisotropy or antiferromagnetic Neél order driven by electrical current through the topological insulator. Magnetic, electronic, structural and chemical characterization of the topological insulator(s) and magnetic insulator(s) post-interfacing is required. Structural and chemical analysis of the interface itself must be included. Analysis of the exchange interaction at the interface itself would be ideal. Delivery of samples is expected for government qualification of the resulting heterostructures. 

PHASE III: If sufficiently high quality heterostructures and interfaces are formed, this effort should further optimize the technique and include topological-magnetic device design and fabrication for energy efficient electronic devices in application areas such as THz detection, switching or energy harvesting. 

REFERENCES: 

1: A. R. Mellnik, J. S. Lee, A. Richardella, J.L.Grab, P. J. Mintun, M. H. Fischer, A.Vaezi, A.Manchon, E.-A.Kim, N. Samarth and D. C. Ralph "Spin-transfer torque generated by a topological insulator" Nature, 511, 449 (2014)

2:  doi:10.1038/nature13534.

3:  Y. G. Semenov, X. Duan and K. W. Kim, "Voltage-driven magnetic bifurcations in nanomagnet-topological insulator heterostructures" Phys. Rev. B 89, 201405(R) (2014)

4:  doi: 10.1103/PhysRevB.89.201405.

5:  Y. G. Semenov, X.-L. Li, and K. W. Kim, "Currentless reversal of Néel vector in antiferromagnets" Phys. Rev. B 95, 014434 (2014)

6:  doi:10.1103/PhysRevB.95.014434

KEYWORDS: Topological Insulator, Magnetic, Epitaxy, Deposition, Heterostructure, Interface, Energy Efficient Electronics, Manufacturing Process, Manufacturing Materials 

TECHNOLOGY AREA(S): Human Systems 

OBJECTIVE: To enhance cognitive and physical performance in warfighters by exploiting single nucleotide polymorphisms 

DESCRIPTION: American soldiers are an elite and highly motivated group of individuals. They face severe cognitive and physical loads while in combat and while preparing for combat. The Army prepares soldiers with both physical and cognitive training. Individual soldiers usually also prepare themselves for training and combat by consuming considerable quantities of nutritional supplements, including vitamins and minerals. Standards for vitamins and minerals were developed in the 1940s and have changed little since then. National recommendations vary widely across the developed world, reflecting the paucity of underlying science. Most importantly, national standards were developed to reflect the needs of an average individual and take no account of genetic variation that dramatically influences needs at an individual level. Furthermore, indiscriminate overconsumption to attempt to compensate for this lack of knowledge leads to both health and performance problems. Advances in DNA sequencing technology have revealed a surprising level of genetic variation between individual humans, with any two humans differing by an average of 3 million single nucleotide polymorphisms. While some polymorphisms are neutral, many others have a metabolic and physiological impact. Over 600 human genes encode critical enzymes that require a vitamin or mineral cofactor. Proper function of these 600 enzymes requires appropriate levels of individual vitamin or mineral cofactors; too much or too little leads to loss of function and downstream metabolic, physiological, and phenotypic effects. Single nucleotide polymorphisms within the exons, promoters and splice sites of these genes alter the amount of the vitamin or mineral cofactor that an individual needs. A typical human has functional polymorphisms in two or more of these critical 600 genes, that alter the amount of cofactor needed for proper enzymatic function. Because of advances in sequencing technologies these polymorphisms can now be rapidly identified and biochemically interrogated. The results of these interrogations of individual single nucleotide polymorphisms can be used to tailor intake of supplements to individual genotypes. The impact of this on the Future Army will be enhanced warfighter cognitive and physical performance. With the advent of inexpensive genome and exome sequencing it is becoming unconscionable to not exploit this new capability. The missing link between individual genomic information and improved performance capabilities is the functional interrogation of single nucleotide polymorphisms in key enzymes that require vitamin or mineral cofactors for proper function. The objective of this SBIR is to functionally interrogate single nucleotide polymorphisms in a subset of the 600 genes that encode critical enzymes that require a vitamin or mineral cofactor in order to identify those variants that affect enzymatic function but that can be remediated with vitamin or mineral supplementation in order to enable enhanced cognitive and physical performance and to protect warfighters from performance-degrading factors. Metabolic tuning through dietary cofactors (i.e. vitamins and minerals) is safe, efficacious, inexpensive, and easy to deliver. 

PHASE I: In phase I the investigators will demonstrate that they have the capability to rapidly, efficiently and rigorously screen comprehensive libraries of human polymorphisms in metabolically important genes whose enzymatic activity is cofactor sensitive. They will demonstrate this by determining, for one common human polymorphism, the impact of the polymorphism and the impact of individually tailored nutritional intervention. Furthermore they will quantify the impact of the polymorphism and the intervention on performance in a young healthy population that is similar demographically to U.S. soldiers. For example, recent work by Manousaki et al (AJHG 2017) confirms other reports that single nucleotide polymorphisms in the human CYPR2R1 gene have large effects on 25-hydroxyvitamin D levels, and individuals with just one synonymous coding variant have a significantly increased risk of vitamin D insufficiency (p = 1.26 x 10-12). Other investigators have previously shown that vitamin D deficiency depresses the immune response to infections, and is also associated with increased mortality from cardiovascular disease, diabetes, multiple sclerosis and some cancers. While cancer, diabetes and stroke are outside the scope of this SBIR topic, 5% of male and 20% of female soldiers develop stress fractures during basic training. A successful phase I could be screening soldiers entering basic training for CYPR2R1 polymorphisms that affect vitamin D levels, prescribing dietary (vitamin) interventions for soldiers with CYPR2R1 polymorphisms that suppress serum vitamin D levels, and documenting the return on investment of this intervention on the incidence of stress fractures in basic training. However, a successful phase I could also instead focus on a different gene and its polymorphisms and quantify the effect of those polymorphisms and tailored interventions on soldier performance and readiness. A demographically similar population may be used instead of U.S. soldiers. 

PHASE II: By the end of phase II the investigators will have comprehensively characterized common polymorphisms in at least fifteen cofactor-dependent enzymes with well-established metabolic importance and impact on human performance. They will characterize the impact of these polymorphisms as well as the impact of remediation. They will provide DoD with qualitative and quantitative measures of the biological, physiological, and economic costs and benefits of assaying these polymorphisms in warfighters. The deliverable is the dataset which will provide the content for immediate implementation for genotyping assays to identify individuals with suboptimal enzymatic activity. The performer will have designed a low cost accurate screening test for individual humans and low cost recommendations for individually tailored nutritional recommendations of FDA approved over the counter supplements to optimize performance capabilities. By the end of phase II the results will be ready for large scale commercial production. The analysis should cost less than $100 per soldier and the analysis should be complete within 24 hours of receiving a soldier’s sample. 

PHASE III: The ability to use tailored regimens of over the counter FDA approved vitamins and minerals in conjunction with precise knowledge of the molecular effects of individual genetic polymorphisms will radically advance human performance capabilities. Today many warfighters seek to be physically and mentally better prepared by consuming vast quantities of vitamins, herbs, and other substances, often with no scientific basis whatsoever and almost certainly with no knowledge of their own genetic variance and biochemical needs. This SBIR will change this behavior from anecdote driven to scientifically based. It is anticipated that civilian athletes, scholars, scientists and engineers, as well as any civilian seeking improve physical or cognitive capabilities will embrace the opportunity for informed nutritional intervention in order to safely and economically enhance and preserve cognitive and physical performance capabilities. 

REFERENCES: 

1: Hustad, S., Midttun, O., Schneede, J., Vollset, S.E., Grotmol, T., and Ueland, P.M. The methylenetetrahydrofolate reductase 677C-T polymorphism as a modulate of a B vitamin network with major effects on homocysteine metabolism. 2007. Am J Hum Genet 80(5): 846-55.

2:  Manousaki, D., et al. Low-frequency synonymous coding variation in CYP2R1 has large effects of vitamin D levels and risk of multiple sclerosis. 2017. Am J. Hum Genet 101(2): 227-238.

3:  Roussotte, F.F., Hua, X., Narr, K.L., Small, G.W., Thompson, P.M., Alzheimer’s Disease Neuroimaging Initiative. The C677T variant in MTHFR modulates associates between brain integrity, mood, and cognitive functioning in old age. 2017. Bio Psychiatry Cogn Neurosci Neuroimaging 2(3): 280-288.

4:  Troesch, B., Weber, P., and Mohajeri, M.H. Potential links between impaired one-carbon metabolism due to polymorphisms, inadequate B-vitamin status, and the development of Alzheimer’s disease. 2016. Nutrients 8(12): 803.

KEYWORDS: Genetic, Variation, Polymorphisms, Metabolism, Performance, Health, Cognition, Cognitive, Biochemistry 

TECHNOLOGY AREA(S): Sensors 

OBJECTIVE: Design and fabricate a resonant cavity midwave infrared (MWIR) detector for a proof of concept that utilizes a patterned metal layer (grating) to selectively enhance the optical absorption of the underlying device. The resulting detector should demonstrate a high quantum efficiency and higher operating temperature than a comparable state-of-the-art device without the grating, thus reducing the size, weight, and power (SWaP) requirements for long range high resolution midwave infrared (IR) imaging sensors. 

DESCRIPTION: Advances in infrared detector technology remain limited by SWaP due to the need for cooling in dewar assemblies for peak performance. In order to provide the benefits of high-performance mid-wave IR imaging to small UAS and infantry weapon systems, sensor cooling requirements must be reduced so that detectors can be incorporated into lightweight sensor packages to enable enhanced awareness and long range object of interest identification in all battlefield conditions. Patterned resonator structures are a well-known concept for creating local enhancements to field intensities in optical structures (see references and related literature). However, current III-V semiconductor technology (bulk and strained layer superlattice) have not yet achieved operation close to room temperature. By combining the latest in device materials and architecture (e.g. unipolar barrier devices) with a novel metal grating on the detector structure that uses optical resonance to greatly enhance the infrared absorption, the total absorber volume required can be reduced, enhancing the signal-to-noise ratio to allow for operation at higher temperatures accessible to thermoelectric cooling or even passive cooling. The overlaying grating pattern must be carefully designed to provide the maximum enhancement at a targeted wavelength for a specific device geometry. If successful, the high-temperature MW detectors enabled by this project will directly benefit the compact imaging sensors supporting the Solider Lethality, Next Generation Combat Vehicle, and Future Vertical Lift Army modernization priorities. 

PHASE I: Design a grating pattern for an antimonide-based MWIR detector using electromagnetic (EM) modeling that results in near-total absorption while also minimizing the required absorber layer thickness of the device. Demonstrate enhanced absorption in a fabricated test structure and accuracy of the EM model. Show that the model and device fabrication can be adjusted for a desired cutoff wavelength. 

PHASE II: Develop a working focal plane array and incorporate in a prototype device, including a readout integrated circuit and conduct testing in a realistic environment. 

PHASE III: The system could be used in a variety of applications where size and portability are paramount. This includes head mounted display systems, which could incorporate infrared sensors to enhance visibility in poor environmental conditions, highlight Identification Friend or Foe (IFF) signals, and to provide advanced warning of hostile activity. Commercial: high-performance MWIR cameras can be applied in commercial vehicle technology, both manned and autonomous. Room temperature MWIR detection can also be packaged in fused video surveillance and home security. 

REFERENCES: 

1: D. Z. Ting, A. Soibel, A. Khoshakhlagh, S. A. Keo, S. B. Rafol, A. M. Fisher, B. J. Pepper, E. M. Luong, C. J. Hill, S. D. Gunapala, Antimonide e-SWIR, MWIR, and LWIR barrier infrared detector and focal plane array development, Proc. SPIE 10624, Infrared Technology and Applications XLIV, 1062410 (2018)

2:  K. K. Choi, M. D. Jhabvala, J. Sun, C. A. Jhabvala, A. Waczynski, K. Olver, Resonator-quantum well infrared photodetectors, Appl. Phys. Lett. 103 (2013)

3:  C. Min, J. Li, G. Veronis, J.-Y. Lee, S. Fan, P. Peumans, Enhancement of optical absorption in thin-film organic solar cells through the excitation of plasmonic modes in metallic gratings, Appl. Phys. Lett. 96 (2010)

KEYWORDS: Sensors, Infrared, Midwave, Optical Grating, Focal Plane Array, Plasmonics 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Prototype solid melanin-based material for additional application testing such as harvesting thermal energy for cold weather vehicle/clothing coating, EMP shielding, radiation shielding/countermeasure/prophylaxis, stored energy & energy release. 

DESCRIPTION: Melanin is a biological polymer that possesses many desirable properties with clear Army applications in dampening radar signatures, EMP shielding, radiation protection, cold condition protection, energy storage/transduction and an alternative circuit material. Naturally produced melanin absorbs energy in many different forms (UV, visible light, ionizing radiation, electromagnetic), binds toxic materials (metals, oxiding agents, free radicals) and provides structural strength. Melanins are believed to be the primary protective mechanism for microorganisms that survive in harsh environments like Chernobyl, Fukushima and Antarctica. Experimental mice injected with melanin survive otherwise lethal doses of gamma irradiation. Melanin absorbs solar radiation and could be used to improve solar panels for energy harvesting. While this material represents extraordinary properties, exploitation for military applications is impossible without scale production of the naturally biologically produced version. Synthetic melanin is estimated to be 40-60% less efficient than naturally derived melanin. Research on industrial production of natural melanin will allow for future structural studies on why synthetic melanin lacks several properties. At the industrial scale, melanotic materials (either naturally or synthetically produced) could yield revolutionary benefits in the battlespace such as inexpensively EMP shielding sensitive equipment, protecting soldiers from the harmful effects of radiation, enhanced mountain and alpine operations, new types of batteries and possibly even explosives. Melanin based coatings can be clearly tied to Army modernization priorities for the Next generation combat vehicle (NGCV) through its EMP/EMR protective properties, Networks through EMP/EMR protective properties and as a possible circuit material and finally soldier lethality through its thermal absorption properties enhancing mountain/alpine operations. 

PHASE I: Conduct a systematic study of naturally produced melanin’s ability to collect, store and release multiple forms of dispersed energy with an emphasis on efficient production. Evaluate shelf-life and safe storage conditions as well. 

PHASE II: Develop scalable production methods while retaining desirable energy transduction properties. The goal is to develop prototype solid melanotic materials (sheets, bricks, powder, etc) that can be further evaluated in military applications. Use of a bioreactor, fermentation vessel or padreactor system at the industrial scale are encouraged. Phase III – Provide at least 1kg of solid, naturally derived, melanin. This will be used to seed additional development in multiple application areas from vehicle/fabric/ building material coatings, body armor and battery packs. As a material that absorbs a very wide range of energy, it may have many, many applications. 

PHASE III: Possible new class of explosive. Melanotic materials are also useful for EMR/EMP shielding and thermal energy absorption. 

REFERENCES: 

1: Casadevall A, Cordero RJB, Bryan R, Nosanchuk J, Dadachova E., Melanin, Radiation, and Energy Transduction in Fungi. Microbiol Spectr. 2017 Mar

2: 5(2). https://doi.org/10.1128/microbiolspec.FUNK-0037-2016

3:  Rageh MM, El-Gebaly RH, Abou-Shady H, Amin DG. Melanin nanoparticles (MNPs) provide protection against whole-body ɣ-irradiation in mice via restoration of hematopoietic tissues. Mol Cell Biochem. 2015 Jan

4: 399(1-2):59-69. doi: 10.1007/s11010-014-2232-y. Epub 2014 Oct 10.

5:  Robertson KL, Mostaghim A, Cuomo CA, Soto CM, Lebedev N, Bailey RF, Wang Z. Adaptation of the black yeast Wangiella dermatitidis to ionizing radiation: molecular and cellular mechanisms. PLoS One. 2012

6: 7(11):e48674. doi: 10.1371/journal.pone.0048674. Epub 2012 Nov 6.

KEYWORDS: Multifunctional Materials, Synthetic Biology, Radiation Protection, EMP Shielding, Protective Coatings, Energy Harvesting 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: To develop a low-cost manufacturing process for the production of metal composite flakes/discs for use as visible and infrared obscurants. Develop and demonstrate a PVD method to produce highly electrically conductive flakes/discs with optimum dimensions in the for IR obscuration. These PVD produced flake/disc materials shall have an electrical conductivity on the order of iron, although a conductivity on the order of copper is preferred. Additionally, the PVD produced material should be appropriately chosen so as to provide attenuation in the visible region of the spectrum, i.e. via absorption. Also, the PVD produced material must not be ‘pyrophoric’ in nature and must be disseminated via hot air turbine smoke generators and explosively disseminated via explosive central burster munitions. Aluminum is an example of material that meets conductivity requirements, is efficiently manufactured via PVD processes but is ‘pyrophoric’ in nature and creates a flaming hazard when disseminated via explosive central burster grenade or hot air turbine smoke generator. Higher density materials may have an advantage over low density materials for volumetric dissemination purposes. Finally, the PVD produced Flake material should provide a means of mitigating particle agglomeration, so that aerosolization is maximized during the dissemination process. Dissemination approaches for the newly developed material shall include pneumatic (e.g. smoke generator) or explosive (e.g. grenade) techniques. There are two essential dimensional requirements for the flakes produced. First, the length requirement is vital for achieving the desired electromagnetic properties. The distribution must be relatively narrow with a major lateral dimension of about 3 µm (+/- 1 µm) in order to produce a strong resonance within the FIR atmospheric transmission window (8 to 12 µm). Second, flake thicknesses should be as thin as possible within the constraints of flake production. This may prove to be in the vicinity of 10-30 nm, although an ideal thickness of 1-2 nm is desired. A realistic goal of this effort is to produce an IR obscurant with extinction coefficients in the 8-20 m2/gram range. 

DESCRIPTION: Smoke and obscurants play a crucial role in protecting the Warfighter by decreasing the electromagnetic signature that is detectable by various sensors, seekers, trackers, optical enhancement devices and the human eye. Recent advances in materials science now enable the production of precisely engineered obscurants with nanometer level control over particle size and shape. Numerical modeling and many measured results on metal flakes affirm that more than order of magnitude increases over current performance levels are possible if high aspect-ratio conductive flakes/discs can be effectively disseminated as an un-agglomerated aerosol cloud. CURRENT STATUS: Aluminum has been demonstrated as a PVD produced material that has high extinction cross-section/unit mass characteristics on the order of 10 m2/gram. Despite its high extinction, aluminum PVD flakes are too pyrophoric and too low in packing density to be practical for dissemination in munitions. Previous efforts with copper PVD processes were unable to produce desired particle dimensions. Novel approaches to generating metal/ disk shapes with the required dimensions is one possible approach that may be integrated into the PVD process. For example, patterning a substrate with a photolithographic technique prior metal deposition is one possible approach to achieving disc/flake shapes. Currently, the best obscurants for IR attenuation are comprised of brass flakes, which have an extinction cross-section/unit mass of 1.4 m2/g. 

PHASE I: Demonstrate with samples an ability to produce PVD produced flakes with major dimensions of 3 µm (+/- 1 µm) microns in length, thicknesses of 10-30 nm, and conductivity of iron or better (10^5 mho/cm). (5) 10-gm samples shall be provided to ECBC for evaluation. 

PHASE II: Demonstrate that the process is scalable by providing 5 1-kg samples with no loss in performance from that achieved with the small samples. In Phase II, a design of a manufacturing process to commercialize the concept should be developed. 

PHASE III: The techniques developed in this program can be integrated into current and future military obscurant applications. Improved grenades and other munitions are needed to reduce the current logistics burden of countermeasures to protect the soldier and associated equipment. This technology could have application in other Department of Defense interest areas including high explosives, fuel/air explosives and decontamination. Improved separation techniques can be beneficial for all powdered materials in the metallurgy, ceramic, pharmaceutical and fuel industries. Industrial applications could include electronics, fuel cells/batteries, furnaces and others. 

REFERENCES: 

1: Bohren, C.F.

2:  Huffman, D.R.

3:  Absorption and Scattering of Light by Small Particles

4:  Wiley-Interscience, New York, 1983.

5:  Takayuki, Nakao, Metal pigment flakes and method for producing metal pigment flakes, PCT Int. Appl. (2015), WO 2015146977 A1 20151001

6:  Embury, Janon

7:  Maximizing Infrared Extinction Coefficients for Metal Discs, Rods, and Spheres, ECBC-TR-226, Feb 2002, ADA400404, 77 Page(s)

8:  Obscurant Applications, S. Johnson, ISN Review, MIT, June 2012.

9:  Bujard, Patrice

10:  U. Berens

11:  Patent WO2006021528 A2

12:  Process for Preparing flake-form pigments based on aluminum and on sioz (z=0.7-2.0), Ciba Sc Holding Ag

13:  Mar 2, 2006

14:  Takayuki, Nakao, Method for producing metallic flake pigment, PCT Int. Appl. (2016), WO 2016047253 A1 20160331

15:  Weinert, H. H,.New developments for the continuous high rate production of Physical Vapor Deposition (PVD) flake pigments without use of consumable substrates, Annual Technical Conference Proceedings - Society of Vacuum Coaters (2006), 49th, 642-647

KEYWORDS: Physical Vapor Deposition, Metals, Infrared Obscuration 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Develop an in-situ manufacturing system for repair or retrofit of existing structures such as railways and bridges with the ability to match or improve upon existing material performance. 

DESCRIPTION: With the demand for persistent readiness of critical infrastructure such as rail and bridge structures, the need for the ability to repair and improve upon existing large metal structures becomes more crucial. These needs range from the ability to repair metal structures with the same material to retrofit with materials exhibiting improved material properties over the existing structure which impart new capabilities to carry heavier loads and/or improve durability. Recent advancements in additive manufacturing have developed several technologies such as cold spray and additive friction stir which provide unique capabilities to deposit material on existing structures and maintain or improve upon the performance characteristics of the original wrought material. The goal of this topic is to develop a system capable of rehabilitating existing structures such as railway rails and bridges using an additive process. The proposed system should not only be able to provide in-situ repair of the base material, but also be capable of improving upon the existing material properties through processes or material improvements. The additive manufacturing repair process needs to have a deposition rate of at least 80 cm3/hr. in order to be economically viable for large structures. 

PHASE I: Demonstrate the feasibility of material repair prototypes which exhibit favorable mechanical properties for structural performance. Develop a few small-scale prototypes using the proposed process for a steel structure. Demonstrate the feasibility of applying the repair/update process to existing structures. Deliver a report documenting the research and development efforts along with a detailed description of the proposed methodology. The most effective process capable of repairing/improving existing structures with the desired material properties will be determined and proposed for phase 2. 

PHASE II: Manufacture the proposed repair technology. Develop a set of small-scale mechanical tests to demonstrate the performance of the developed repair process. Apply the proposed rehabilitation methodology to a damaged steel structure as a repair method and demonstrate the repaired area has comparable properties to that of the original structure. Demonstrate that the technology could be used on a wide range of structure geometries and open environments. Determine the effects of varying specific structure/composition parameters on the mechanical performance of the prototype. Develop a parametric study which systematically varies the composition, microstructure, and processing of the material to determine the conditions for manufacturing operations. In addition, determine the environmental stability of the backing material: relevant variables to consider are temperature, corrosion resistance, and effects of strain rate. Deliver a reporting document: (1) the formulation, composition and process for fabrication of the repaired structure; (2) the experimental procedures and results that demonstrate the process meets the performance requirements; (3) the experimental procedures and results showing the repaired material meets the performance requirements. A favorable performance evaluation will lead into Phase III applications. All research, development, and prototype designs shall be documented with detailed descriptions and specifications of the composition, fabrication, microstructure, and mechanical performance of the prototype repair materials. 

PHASE III: The development of a process capable of repairing/improving on existing railway and bridge systems has a wide range of applications in both the military and civil works areas as well as in both government and private sectors. A metal repair process such as this could also potentially be used for in-situ repair of ships or complex parts such as submarine propellers, automotive parts, etc. The process could also be used in a wide range of coating applications. The ability to repair an existing structure in-situ with a metal additive process opens an endless amount of possibilities for applications. 

REFERENCES: 

1: [l] D. M. Frangopol and M. Liu, "Maintenance and management of civil infrastructure based on condition, safety, optimization, and life-cycle cost*," Struct. Infrastruct. Eng., vol. 3, no. 1, pp. 29-41, Mar. 2007.

2:  [2] 0. G. Rivera et al., "Influence of texture and grain refinement on the mechanical behavior of AA2219 fabricated by high shear solid state material deposition," Mater. Sci. Eng. A, vol. 724, pp. 547-558, May 2018.

3:  [3] S. Palanivel and R. S. Mishra, "Building without melting: a short review of friction-based additive manufacturing techniques," Int. J. Addit. Subtractive Mater. Manuf , vol. 1, no. 1, p. 82, 2017.

4:  [4] E. Irissou, J.-G. Legoux, A. N. Ryabinin, B. Jodoin, and C. Moreau, "Review on Cold Spray Process and Technology: Part I-Intellectual Property," J. Therm Spray Technol., vol. 17, no. 4, pp. 495-516, Dec. 2008.

5:  5] C. A. Widener, 0. C. Ozdemir, and M. Carter, "Structural repair using cold spray technology for enhanced sustainability of high value assets," Procedia Manuf , vol. 21, pp. 361-368, 2018.

TECHNOLOGY AREA(S): Bio Medical 

OBJECTIVE: To develop and demonstrate a technology enabling the detection and quantification of modified nucleic acid bases from a mammalian genome such as methylation sites. The method shall be in an easy-to-use format, not too technically demanding, and require instrumentation with minimal analytics. The method should enable the assessment of DNA methylation targeting a particular region or gene of interest as oppose to discovery of unknown epigenetic changes. 

DESCRIPTION: DNA methylation is the study of chromosomal patterns of DNA or histone modification by methyl groups in vertebrates. The cytosine (C) base in DNA and lysine residue in histone tails can be methylated. These modifications are considered very stable, heritable, and are correlated with locus specific transcriptional status. DNA methylation can also impact gene expression, particularly if the methylation is present in CpG islands, which are found in approximately 50% of promoters. DNA methylation alters gene expression levels primarily through regulating methylation state-dependent interactions with transcriptional activators or repressors, and chromatin remodeling enzymes. There are multiple events that can impact DNA methylation machinery. These biomarkers can be used at any stage of a disease and can be associated with its cause (risk biomarkers), onset (diagnostic biomarkers), clinical course (prognostic biomarkers), or response to treatment (predictive biomarkers). To date vast majority of DNA methylation are reported in cancer research and recently DNA methylation has been known to show a significant role in the pathophysiology of several other diseases such as PTSD (Hammamieh et al 2017), aging ( Hovarth et al 2013) as well as neurodegenerative disorders (Levenson et al 2011). There is a growing body of literature suggesting a role for epigenetic factors as a molecular link between environmental factors and type 2 diabetes. Multiple technologies exist by which these differences can be measured. Most of these methods detect the global DNA methylation or overall changes in DNA methylation status of the sample (1). Bisulphite sequencing that is considered the gold standard method for the detection and quantification of DNA methylation and is similar to genomic sequencing with regards to its prohibitive cost and difficulty in data analysis. To perform a targeted region sequencing, primers are designed that are specific for bisulphite converted DNA; It is a quick method, which could be used for simultaneously profiling of multiple samples/multiple regions (Zymo research, (5)). The obvious drawbacks of the current methods are that they are all time intensive and involve the use of multiple equipment with specialized training. Less common is the detection of methylated bases directly through sequencing of unmodified DNA that could be done without enrichment or bisulfite conversion. Considering the detailed procedure of bisulphite modifications, direct detection of modified bases would be a preferred approach. Another approach for methylated DNA fractions of the genome, usually obtained by immunoprecipitation, could be used for hybridization with microarrays ( 1, 4, 5 ). This is the most popular method which fills that gap between whole genome bisulfite sequencing and cumbersome low throughput methods that can access the methylation of a pre-designed individual CpG sites and can be customized to region of interest. Pyrosequencing is another technology where individual primers are designed to get a short-read pyrosequencing reaction of around 100 bp. The level of methylation for each CpG site within the sequenced region is estimated based on the signal intensities for incorporated dGTP and dATP. The result is quantitative, and the technique is able to detect even small differences in methylation (down to 5%). It is a good technique for heterogeneous samples but requires specialized equipment and training. Advancement in the development of nanopore-based single-molecule real-time sequencing (2-3) technology (Oxford nanopore) can help to detect modified bases directly in short time. Commercialization of each or combination of the unique technique will bring the next generation of assay with even better sensitivity and specificity that would be easy to perform and analyze. The aim of this STTR is to develop a method of choice that should deliver an unbiased answer to the biological question being asked by the researcher. It will be important to consider following factors when choosing a method for targeted DNA methylation analysis: 1) The development of an automated procedure; 2) The investigation is on known methylation sites for specific gene of interest 3) The amount of sample requirements. Considering clinical samples, whole blood would be sample of choice. 4) The sensitivity and specificity of the assay proposed; 5) The robustness and simplicity of the method. 6) The simplicity of software for analysis and interpretation of the data; 7) Effortless use of specialized equipment and reagents; 8) Turn-around time to result 9) Assay cost. 

PHASE I: Given the short duration of Phase I, this phase should not encompass any human use testing that would require formal IRB approval. Phase I should focus on system design for rapid detection of targeted methylation sites using any gene/region of interest. At the end of this phase, a working prototype of the assay (s) should be completed and some demonstration of feasibility, integration, and/or operation of the prototype. In addition, descriptions of data analysis and interpretations concept and concerns should be outlined. Phase I should also include the detailed development of Phase II testing plan. 

PHASE II: During this phase, the integrated system should undergo testing using some targeted genes/regions of interest for evaluation of the operation and effectiveness of utilizing an integrated system and its capability to demonstrate the utility in a diseased condition such as PTSD. Accuracy, reliability, and usability should be assessed. This testing should be controlled and rigorous. Statistical power should be adequate to document initial efficacy and feasibility of the assay. This phase should also demonstrate evidence of commercial viability of the tool. Accompanying the application should be standard protocols and procedures for its use and integration into ongoing programs. These protocols should be presented in multimedia format. 

PHASE III: The ultimate goal of this topic is to develop and demonstrate a technology enabling the direct detection of modified bases such as methylation sites. This assay format should also be seamlessly integrated so that it can be used as monitoring tools for long term health assessment. Once developed and demonstrated, the technology can be used for identification of risk, diagnostic, prognostic, monitoring and/ or predictive biomarkers for diseased state. Development of new technique for methylation analysis will open a multitude of possibilities for biomarker development and might become extremely valuable in clinical practice. 

REFERENCES: 

1. Hammamieh R, Chakraborty N, Gautam A, et al. Whole-genome DNA methylation status associated with clinical PTSD measures of OIF/OEF veterans. Translational Psychiatry. 2017;7(7):e1169-. doi:10.1038/tp.2017.129.; 2. Simpson, J. T., Workman, R. E., Zuzarte, P. C., David, M., Dursi, L. J., & Timp, W. (2017). Detecting DNA cytosine methylation using nanopore sequencing. Nature Methods, 14, 407. doi: 10.1038/nmeth.4184; 3. Wilmot, B, et al. (2015) Methylomic analysis of salivary DNA in childhood ADHD identifies altered DNA methylation in VIPR2. The Journal of Child Psychology and Psychiatry. Doi: 10.1111/jcpp.12457; 4. https://www.biomerieux-usa.com/clinical/biofire-film-array https://www.youtube.com/watch?v=KjAeOzTL1wo; 5. Dean et al Multi-omic biomarker identification and validation for diagnosing warzone-related Post-Traumatic Stress Disorder. Submitted to Science Translational Medicine; 6. Levenson VV. DNA methylation as a universal biomarker. Expert Rev Mol Diagn. 2010;10(4):481-8.; 7. Horvath S. DNA methylation age of human tissues and cell types. Genome Biol. 2013;14:R115. doi: 10.1186/gb-2013-14-10-r115

KEYWORDS: Epigenetics, Methylation, Next-generation Sequencing, Technology, Military Health 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: The objective of this topic is to develop products that can store and deliver heat without the need for power. 

DESCRIPTION: Extremity protection for the current Extended Cold Weather Clothing System (ECWCS) utilizes a series of garments designed to be worn within tightly defined temperature ranges. For the hands, Soldiers can increase protection by switching from gloves to mittens. A similar option exists for wearing boots with progressively higher levels of insulative capabilities. The trade off to higher insulation under the current system is the loss of dexterity and increased weight, both of which impact mission execution and success. Improvements in thermal extremity protection will offer a cognitive benefit to Soldier performance as well as enable better dexterity for operations—such as shooting— which combined will improve Soldier lethality in extreme operating conditions. Many athletic and sportswear companies are now selling garments with built-in heating elements, from socks and gloves to full jackets, thus allowing a wearer to maintain thermal comfort with less bulk. However, to date, the majority of these systems require the use of power. In addition to the power challenge, many systems are not Berry amendment compliant, limiting procurement options. The focus of efforts under this topic call will be on developing material systems that can store and deliver heat to a Soldier in the field without the need for a power input. Material systems must be able to be recharged for additional heat release cycles in a field or deployed setting. 

PHASE I: Phase I of the proposal must demonstrate feasibility of the technical approach through development of a preliminary material concept. The material must demonstrate successful heat release that is initiated without a power input. The heat release must be compatible with applications adjacent to human skin without the risk of burns (< 44° C for direct contact systems over 6 hours). By the end of Phase I, a feasibility study of scale up must be completed, including an estimate of material cost. There must also be a coherent prototype design for fabrication in later Phases. Sample material (3 prototypes or formulations) must be delivered at the end of Phase I. Heat generation should be sustainable for at least 3 hours. Number of recharges during the life of the material is to be estimated. Technologies at the end of Phase I should be at TRL 4. 

PHASE II: Phase II will focus on scale up of the successful Phase I technology into prototypes for lab and field simulated evaluation. Prototypes and material must demonstrate successful heat storage and release for at least 3 hours. The form factor of the prototype is left to the discretion of the principal investigators (PI). Prototype materials must demonstrate consistent function in varying environmental exposures (high humidity, wind, etc), including after pro-longed exposure to temperatures as low as -40 ⁰ C. The final deliverable must also include a commercialization assessment and the viability of mass production for the technology. Deliverables to include production cost estimate, technical data package, final report, and 3 prototypes. Technologies at this stage should be at a TRL 4 to 5. 

PHASE III: Phase III will demonstrate scalability and operational application of the proposed technology. The technology developed under this effort has direct application to Soldier operational clothing and individual equipment. The results of this effort may culminate in a material that can be fielded as an insert to complement the current ECWCS system or could be directly integrated into the textile layers of the ECWCS. While the focus of this effort is use at the Soldier level, technologies could be extrapolated to other military applications, for example, maintenance of military equipment in cold temperatures for optimal performance, icing prevention of critical tools, weapons, and equipment etc. Successful materials may also find commercial applications in passive or latent heat storage for energy optimization systems and infrastructure maintenance (thermal regulation, ice prevention etc), recreational gear for cold weather activities, and non-military police and rescue forces. 

REFERENCES: 

1: Holmer et al, 2010, International Journal of Occupational Safety and Ergonomics (JOSE), 16(3), 387–404, "A Review of Technology of Personal Heating Garments" https://doi.org/10.1080/10803548.2010.11076854

2:  Riffat et al, 2015, Renewable and Sustainable Energy Reviews, 41, 356-367, "The Latest Advancements on Thermochemical Heat Storage Systems" https://www.sciencedirect.com/science/article/pii/S1364032114007308

3:  Ghafoor et al, 2016, Energy Conversion and Management, 115, 132-158, "A Review of the Performances Enhancement of PCM Based latent heat Storages System within the Context of Materials, Thermal Stability and Compatibility" https://www.sciencedirect.com/science/article/pii/S0196890416300759

4:  Zeiler et al, 2014, Proceedings of the 8th Windsor Conference, "personal heating

5:  energy use and effectiveness" http://nceub.org.uk/W2014/webpage/W2014_index.html

KEYWORDS: Personal Heating, Thermal Comfort Management, Powerless Heating 

TECHNOLOGY AREA(S): Ground Sea 

OBJECTIVE: Develop a system that produces hydrogen from water and exposure to sunlight without any additional energy input that is ready to use in fuel cell or storage applications. 

DESCRIPTION: The Army has been investigating hydrogen fuel cells for vehicle power applications (both primary and non-primary) due to their reduced acoustic and thermal signatures as well as high power density and unlimited run time (provided fuel is supplied). Unlike current logistic fuels, hydrogen needs to be extracted from a source before it can be used, as it is not abundantly available in a usable form naturally. Numerous methods for hydrogen generation have been investigated in the past few decades, most usually requiring external energy to produce the hydrogen and treatment to remove compounds that could damage a fuel cell if passed through. Recent advances in technology have suggested that producing hydrogen from water with direct exposure to sunlight may be an attractive path for hydrogen generation. A system is desired to produce hydrogen from water and exposure to sunlight with no external energy input, just sunlight. The system should produce hydrogen that is of sufficient purity for proton exchange membrane (PEM) fuel cell use (99.999% pure). The hydrogen produced by the system should be ready to use in a fuel cell application or passed to a compressor/hydrogen storage system. The system should also be able use greywater or wastewater as a hydrogen source. The system should maximize hydrogen production per unit area, minimizing the total area of the system. 

PHASE I: The desired results of Phase I work are a preliminary design of the system and a small-scale demonstration of the underlying technologies and design. Specifically, the efficiency of the water splitting process, the hydrogen separation and collection, and proposed operations and control of the system should be demonstrated. These demonstrations do not need to be performed in concert with each other but should be performed at a small scale to demonstrate the feasibility of the design. The system should minimize both area and weight while providing the desired flow rate of hydrogen. 

PHASE II: The desired result of Phase II is a system that produces 1 kg of hydrogen per day assuming 6 hours of sun exposure per day. The system should be optimized for continuous operation and provide hydrogen that can be used in a PEM fuel cell system or compressed and stored for later use in such a system. A demonstration of the system will be performed in conjunction with a fuel cell system and/or a hydrogen storage apparatus. Hydrogen purity will be measured as well as overall system efficiency. A study should be undertaken to develop a plan to scale up the system to a higher production rate. Key difficulties in production and scale up should be identified and mitigations proposed and examined, when possible. 

PHASE III: Phase III would result in a portable, self-powered, high output hydrogen generation system. A scaled up system could support operational refueling of future hydrogen vehicles, enabling enhanced silent watch and mobility capabilities along with increasing lethality and survivability. Potentially larger systems could be developed for larger facilities and staging areas, further enhancing the capability. Commercially, this system could be used to augment the hydrogen economy infrastructure and lead to clean, potentially remote hydrogen generation and refueling stations. This technology would contribute to energy security and reduce pollution via increased zero emissions vehicles. 

REFERENCES: 

1: Sheng Chu, Wei Li, Yanfa Yan, Thomas Hamann, Ishiang Shih, Dunwei Wang, Zetian Mi, Roadmap on solar water splitting: current status and future prospects, Nano Futures 1, 022001, September 2017.

2:  Faqrul A. Chowdhury, Michel L. Trudeau, Hong Guo, Zetian Mi, A photochemical diode artificial photosynthesis system for unassisted high efficiency overall pure water splitting, Nature Communications 9, 1707, April 2018.

KEYWORDS: Hydrogen, Hydrogen Production, Solar, Water Splitting 

TECHNOLOGY AREA(S): Ground Sea 

OBJECTIVE: Develop a High Performance, Non-flammable Li-ion Battery (LIB) with improved safety and lower thermal management requirements, while maintain / increase the Power, Energy and Cycle life performance of state of the art Li-ion batteries. 

DESCRIPTION: Increased electrification of Army ground vehicles has the potential to increase fuel efficiency and enable integration of higher performance lethality and survivability systems including Directed Energy Weapons and Active Protection Systems. However a significant limitation to electrification are the safety risks and thermal management requirements of the current generation Li-ion battery (LIB) based Energy Storage System (ESS). LIBs utilize highly flammable, volatile electrolytes that can react with electrodes resulting in thermal runway and subsequent catastrophic failure. To mitigate this risk, ESS utilize thermal management and charge / discharge limitations to minimize failure events. They are also packaged in specifically engineered battery enclosures and located to minimize platform damage in the event of LIB failure. However these mitigation measures result in the platform incurring increased weight, volume and / or performance limitations. Recently, a non-flammable Li-ion electrolyte , , has been demonstrated with acceptable Power/ Energy density and Cycle life performance. This is a significant technical advancement in ESS systems as the development of non-flammable chemistry enables LIBs to be packaged in new form factors (e.g conformal linings) and located anywhere (e.g. crew compartment). It is expected that the successful transition of this technology to DOD applications would result in increased energy storage on a platform, lower weight, volume and cooling requirements and earlier / cheaper safety certification. 

PHASE I: A preliminary design based on initial experimental data (e.g. flash point measurements, cell polarization) and modeling showing the feasibility to meet non-flammability rating and meet / improve existing ESS performance metrics in a with a specific focus on Power Density (880W/kg), Energy Density (72Wh/kg), Cycle life (1000), Charge rate (1C) and Discharge rate (2C). Successful accomplishment of this phase includes meeting and demonstration of the aforementioned ESS metrics and delivery of button cells for evaluation / verification. 

PHASE II: Increased design maturity, additional experimental data (e.g. Accelerated Rate Calorimetry) and simulation results (e.g Battery module thermal modeling) to result in interim and final delivery of prototype batteries / cells. The final deliverables and data should support / verify a pathway to meet / exceed the MIL-PERF-32565 90AH LIB performance specifications4. It is expected that the final prototype deliverable (battery / cell) will be safer than MIL-PERF-32565 Type 1 LIBs and should result in a battery / cell demonstrating a SAE J2464 Hazard Severity Level rating is < 3 (nail penetration / overcharge abuse, battery projectile penetration)4. Successful accomplishment of this phase includes meeting aforementioned goals as well as cost competitive technology implementation in a 6T format. 

PHASE III: The end state of the research is the transition of the High Performance, Non-flammable Lithium Battery technology to DOD acquisition programs including US ARMY Program Executive Office Ground Combat Systems / PM Stryker. It is expected that development of a safer LIB will enable quicker and cheaper platform integration and SG-270 / S9310 safety certification for Naval transportation. Furthermore this technology can be transitioned to ARMY’s Next Generation Combat Vehicle hybrid platforms (PM NGCV) as it will have lower safety risk. Successful accomplishment of this phase includes OEM integration on combat vehicle platform to demonstrate capability to PM. 

REFERENCES: 

1: Yang et al., Joule 1, 122–132, September, 2017

2:  Li et al., J Power Sources 394, 26-34, (2018)

3:  Zeng et al., Nature Energy 3, 674-681(2018)

4:  MIL-PERF-32565

KEYWORDS: Power, Energy, Battery, Fuel Efficiency, Rechargeable, Safety, Li Ion, Storage 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: This is an AF Special Topic partnership between AFOSR and AFWERX, please see the above AF Special Topic instructions for further details. A Phase I award will be completed over 3 months with a maximum award of $25K and a Phase II may be awarded for a maximum period of 12 months and $200K. The objective of this topic is to provide an established accelerated technology transition pathway for promising science and technology under development by university teams (undergraduate, graduate, doctorate, post-doctorate, faculty/staff). This includes, but is not limited to, those that have participated in a government sponsored innovation event such as: I-Corp teams, Defense Enterprise Science Initiative, AFRL University Challenge, Hacking For Defense, Hack-A-Thon, etc. This topic is intentionally broad in scope, directed at disruptive innovative advancements that may not be covered by any other specific STTR topic, and designed to explore options for supplementing and expanding public/private partnerships capability with the Air Force Office of Scientific Research. The goal is to stimulate science and technology innovation, foster greatly accelerated technology transfer thru cooperative R&D, and increase private sector commercialization of innovations derived from federal R&D. This topic is aimed at early stage teams (e.g. university teams, research spin-offs or very early stage companies) that have an Minimum Viable Product (MVP) and have partnered with a university or non-profit organization who can help them take their prototype and turn it in to a sustainable business (e.g. university entrepreneurship centers, technology transfer offices, non-profit entrepreneurship institutions). 

DESCRIPTION: Academia is producing disruptive science and technology innovations at an increasingly rapid pace. Hence, rather than utilizing a pre-defined requirements approach, this topic is intended to be an open call for ideas and technologies that may not be currently listed (i.e. the unknown-unknown) under STTR topics, but nonetheless still fit within broad interest areas of the Air Force Office of Scientific Research (AFOSR). These broad areas (Engineering and Complex Systems, Information and Networks, Physical Sciences, and Chemistry/Biological Sciences) are covered in greater detail at https://www.wpafb.af.mil/Welcome/Fact-Sheets/Display/Article/842026/. To be eligible, offeror(s) must be teams that have formed companies and partnered with a university (e.g. university entrepreneurship centers, university technology transfer offices). The offeror should demonstrate their technical capability by demonstrating a credible and high-potential minimum viable product (MVP) along with a credible plan for developing the prototype to a commercially available solution. This topic is not looking for fully formed products, and it is acceptable if the solutions are earlier stage. If the offeror has a later stage solution that already has paying customers, it may make more sense to apply to the SBIR ‘Open Innovation Topic’ AF19.2-001. The offeror should demonstrate their ability to perform the Phase I research by showing that they have an understanding of which Air Force stakeholders could make use of their solution. In general, it will be beneficial to be more specific about the stakeholder, (i.e. listing a person’s name and their exact position and organization is better than just saying ‘pilots could use this’). For early-stage (e.g. student) teams who have never learned about the Air Force and are unsure of where to start, we recommend reaching out to AFWERX (https://www.afwerx.af.mil). The offeror should demonstrate their commercialization capability by demonstrating the results of the commercialization efforts of their partner university or non-profit partner (i.e. a university entrepreneurship center, tech transition office, non-profit entrepreneurship center) and showing a credible plan for turning the prototype or MVP into a sustainable business. It will also be important to show the potential for commercialization in the non-defense market (i.e. Dual-Use technologies). FOCUS AREAS: While This topic is open to all research areas and business ideas that meet the above criteria, there are some areas that are of particular interest to the Air Force right now, these are listed below. If your solution may meet one of these focus areas, please list the focus area number in your proposal FA-001 Quantum Computing: Due to its rapidly emerging nature and increasing impact to all science and technology, this topic also includes a special focus area of consideration for quantum science. Submission topics could include quantum sensing, quantum communications and quantum computing. Possible applications include quantum navigation sensors, quantum clocks for more precise and robust communications and quantum computational algorithmic solutions to tasks such as aircraft radar cross-section, computational aerodynamics and software verification and validation FA-002 Artificial Intelligence(AI) : Due to the increased importance of AI in many areas that the Air Force works in, this is a focus area for this topic. More information on the Air Force’s interest in AI can be found below in the attachment to this topic titled: Summary of the 2018 Department Of Defense Artificial Intelligence Strategy. If you believe your solution can help address one of the ‘Focus Areas’, please note this on the first slide of your application slide deck AND please include the Focus Area ID # in your ‘Keywords’ in the online SBIR application (Example: FA-001). The alignment between a proposal and a Focus Area can strengthen an application. This also does not preclude companies who are looking to solve other problems that are not listed in the Focus Areas to submit to this topic, it is simply intended to give indications of areas of special focus for the Air Force at this particular point in time. 

PHASE I: Validate the product-market fit between the proposed solution and a potential US Air Force stakeholder and define a clear and immediately actionable plan for running a trial with the proposed solution and the proposed US Air Force customer. The period of performance for Phase I is targeted at under an academic semester (ideally 3 months or less) with monetary awards in Phase I not to exceed $25k. This feasibility study should directly address: 1. Offeror(s) must focus on who the prime potential US Air Force end user(s) is and articulate how they would use your solution(s) (i.e., the one who is most likely to be an early adopter, first user, and initial transition partner). 2. Deeply explore the problem or benefit area(s) which are to be addressed by the solution(s) - specifically focusing on how this solution will impact the end user of the solution. 3. Define clear objectives and measurable key results for a potential trial of the proposed solution with the identified Air Force end user(s). 4. Identify any additional specific stakeholders beyond the end user(s) who will be critical to the success of any potential trial. This includes, but is not limited to, program offices, contracting offices, finance offices, information security offices and environmental protection offices. 5. Describe if and how the demonstration can be used by other DoD or governmental customers. 6. Development of plans for MVPs, prototypes, manufacturing, distribution and scaling of the idea into an actual solution for DoD customers. 7. Development of the business, including interest from non-governmental customers, potential sources of private funding, and formation of the team (to include new employees, partners, advisors and investors). The funds obligated on the resulting Phase I STTR contracts are to be used for the sole purpose of conducting a thorough feasibility study using scientific experiments, laboratory studies, commercial research and interviews. MVPs or Prototypes may be developed with STTR funds during Phase I studies to better address the risks and potential payoffs in innovative technologies. Phase I will conclude with a short report and video outbrief and/or telecon with select members of the Air Force Office of Scientific Research. 

PHASE II: Develop, install, integrate and demonstrate a prototype system determined to be the most feasible solution during the Phase I feasibility study. If selected, Phase II awards will be granted up to $200k and are targeted for periods of performance less than one year in duration. This demonstration should focus specifically on: 1. Evaluating the proposed solution against the objectives and measurable key results as defined in the Phase I feasibility study. 2. A clear transition path for the proposed solution that takes into account input from all affected stakeholders including but not limited to: end users, engineering, sustainment, contracting, finance, legal, and cyber security. 3. Specific details about how the solution can integrate with other current and potential future solutions. 4. How the solution can be sustainable (i.e. supportability) 5. Clearly identify other specific DoD or governmental customers who want to use the solution 6. Clearly identify other non-governmental customers who want to use the solution. 

PHASE III: The student-led team small business will pursue commercialization of the various technologies developed in Phase II for transitioning expanded mission capability to a broad range of potential government and civilian users and alternate mission applications. Direct access with end users and government customers will be provided with opportunities to receive Phase III awards for providing the government additional research & development, or direct procurement of products and services developed in coordination with the program. NOTES: a. This SBIR is NOT awarding grants, it is awarding contracts, when registering in SAM.gov, be sure to select ‘YES’ to the question ‘Do you wish to bid on contracts?’ in order to be able to compete for this SBIR topic. If you are only registered to compete for grants, you will be ineligible for award under this topic. For more information please visit https://www.afwerx.af.mil/sbir.html b. We are working to move fast, please register in SAMs and if already registered please double check your CAGE codes, company name, address information, DUNS numbers, ect. , If they are not correct at time of submission, you will be ineligible for this topic. In order to ensure this, please include, in your 15-slide deck, a screenshot from SAM.gov as validation of your correct CAGE code, DUNS number and current business address along with the verification that you are registered to compete for All Contracts. It is the responsibility of the contractor to ensure that the data in the proposal and the data in SAM.gov are aligned. For more information please visit https://www.afwerx.af.mil/sbir.html c. Please note that each company may only have one active ‘Open Topic’ award at a time. If a company submits multiple technically acceptable proposals, only the proposal with the highest evaluation will be awarded. If multiple proposals are evaluated to be equal, the government will decide which proposal to award based upon the needs of the Air Force. The ‘DoD SBIR/STTR Programs Funding Agreement Certification’ form must be completed and signed at the time of *Proposal Submission* and can be found at https://www.afsbirsttr.af.mil/Programs/Phase-I-and-II/ *****Proposals submitted under this topic may relate to technologies restricted under the International Traffic in Arms Regulation (ITAR) which controls defense-related materials/services import/export, or the Export Administration Regulation (EAR) which controls dual use items. Foreign National is defined in 22 CFR 120.16 as a natural person who is neither a lawful permanent resident (8 U.S.C. § 1101(a)(20)), nor a protected individual (8 U.S.C. § 1324b(a)(3)). It also includes foreign corporations, business associations, partnerships, trusts, societies, other entities/groups not incorporated/organized to do business in the United States, international organizations, foreign governments, and their agencies/subdivisions. Offerors must identify Foreign National team members, countries of origin, visa/work permits possessed, and Work Plan tasks assigned. Additional information may be required during negotiations to verify eligibility. Even if eligible, participation may be restricted due to U.S. Export Control Laws. NOTE: Export control compliance statements are not all-inclusive and do not remove submitters’ liability to 1) comply with applicable ITAR/EAR export control restrictions or 2) inform the Government of potential export restrictions as efforts proceed.***** 

REFERENCES: 

1: FitzGerald, B., Sander, A., & Parziale, J. (2016). Future Foundry: A New Strategic Approach to Military-Technical Advantage. Retrieved June 12, 2018, from https://www.cnas.org/publications/reports/future-foundry

2:  Blank, S. (2016). The Mission Model Canvas – An Adapted Business Model Canvas for Mission-Driven Organizations. Retrieved June 12, 2018, from https://steveblank.com/2016/02/23/the-mission-model-canvas-an-adapted-business-model-canvas-for-mission-driven

3:  US Department of Defense. (2018). 2018 National Defense Strategy of the United States Summary, 11. Retrieved from https://www.defense.gov/Portals/1/Documents/pubs/2018-National-Defense-Strategy-Summary.pdf

4:  Torrance, W. E. (2013). Entrepreneurial campuses: Action, impact, and lessons learned from the Kauffman campuses initiative. Retrieved from https://www.kauffman.org/-/media/kauffman_org/research-reports-and-covers/2013/08/eshipedcomesofage_report.pdf

5:  USAF Scientific Advisory Board Study. (2015). Utility of Quantum Systems for the Air Force – Study Abstract. Retrieved from https://www.scientificadvisoryboard.af.mil/Portals/73/documents/AFD-151214-041.pdf?ver=2016-08-19-101445-230

6:  The Joint Artificial Intelligence Center (JAIC). (2018). SUMMARY OF THE 2018 DEPARTMENT OF DEFENSE ARTIFICIAL INTELLIGENCE STRATEGY. Retrieved from https://media.defense.gov/2019/Feb/12/2002088963/-1/-1/1/SUMMARY-OF-DOD-AI-STRATEGY.PDF

KEYWORDS: Open, Other, Disruptive, Innovation, Defense Related Technologies, Quantum Computing 

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Model and understand the kinetic evolution of microstructures within High Entropy Alloys and Chemically Complex Alloys under complex thermal and kinetic additive manufacturing processes. This understanding will provide critical phase evolution and kinetic parameters for optimizing oxidation resistant and high strength ceramic and metallic materials for high temperatures. 

DESCRIPTION: High entropy and chemically complex alloys have exhibited tremendous potential for use in high strength and/or high temperature areas [1-4]. This includes uses for oxidation resistant and high strength applications. However critical information on phase interactions and evolution resulting from controlled thermal processes such as additive manufacturing remain unknown. Recent work has emphasized the potential for complex refractory oxides to facilitate sluggish oxidation kinetics at high temperatures, in many cases, without requiring the formation of classically protective, continuous oxide scales. While this is a promising observation, there exists a large foundational knowledge gap regarding the controlling mechanisms for phase evolution and the inherent structural/chemical oxide attributes. In addition, HEAs with concentrated compositions are designed to exploit the combination of precipitation strengthening, composite multi-phase strengthening, with novel deformation mechanisms in the matrix, such as deformation twinning (TWIP) effects and transformation induced plasticity (TRIP). This can potentially lead to higher strength, higher strain hardenability, and higher uniform elongation/tensile ductility. However the impact on composition and phase evolution is needed to properly optimize material combinations and identify potential valuable material combinations. This project is aimed at developing the models for phase interactions and evolutions within multi-principal element alloys under controlled thermal processing. Additive manufacturing offers novel processing approaches that control thermal processing within refined spatial regions, providing advanced diffusion control for developing composition gradients, non-equilibrium phases, and unique phase interactions. The use of these methods offers a tremendous opportunity to further develop our understanding of HEA phase evolution and behavior. 

PHASE I: The overall modeling approach for selected material combinations, including potential high entropy alloys/multiple principle element alloys will be developed for various additive manufacturing process windows. This includes identifying energies and interactions associated with materials processing, and determination of characterization steps for evaluating materials and microstructures (meso, continuum, and macro levels). The use of additive manufacturing to develop complex phases, composition gradients, and non-equilibrium phases will be evaluated. 

PHASE II: Selected materials will be produced and characterized to validate and verify phase evolution and kinetic microstructure models using the additive manufacturing processes identified from Phase 1. Mechanical properties will also be evaluated and modeled, employing deformation and/or oxidation mechanisms. Phase interactions and compositions will be characterized. The resulting basic understanding will be used to connect and optimize microstructure and mechanistic interactions. In addition, thermodynamic information will be provided for commercial computational data bases to enable equilibrium and metastable composition predictions. 

PHASE III: If warranted, the validated and verified models will be incorporated into crystal plasticity and material processing models for use by academic and industry partners for optimizing thermal processing. Basic science from energy and thermal conditions will be used to develop additive processing inputs for controlling phase evolution. 

REFERENCES: 

1. Miracle, D.B. , and O.N. Senkov, "A critical Review of High Entropy Alloys and Related Concepts", Acta Materialia 122, 488-511 (2017).; 2. Kumar, A., and M. Gupta, "An insight into evolution of light weight high entropy alloys: A review", Metals 6, (9) (2016).; 3. Soni, V, Gwalini, B, Senkov, O.N., Viswanathan, B, Alam, T, Miracle, D.B., Banergee, R, "Phase stability as a function of temperature in a refractory high-entropy alloy", JMR, v 33, iss 19, pp. 3235-3246.; 4. Senkov, O.N., Miracle, D.B., Chaput, K.J., and Couzinie, J.P., "Development and exploraiton of refractory high entropy alloys - A Review", JMR, v 33, iss 19, pp. 3092-3128.

KEYWORDS: Additive Manufacturing, High Entropy Materials, Multiprinciple Element Alloys 

TECHNOLOGY AREA(S): Sensors 

OBJECTIVE: Develop techniques for radar resource allocation for closed-loop radar detection and tracking 

DESCRIPTION: Onerous challenges imposed by an A2AD environment call for closed loop radar operation for concurrent detection and tracking of targets from single and distributed radar systems. In the context of the sense-learn-adapt framework or perception-action framework, this necessitates the use of past data to determine future radar illumination and data collection. Current techniques do not optimally and automatically balance the need to detect, track, and identify targets. Recently, cognitive radar [1-3] approaches have been used to compute sensing actions that are expected to maximize the utility of the received data. Similarly, past efforts on information-theoretic sensor management [3] have produced a framework for managing the resources of an agile sensor, where the utility of the sensing action is judged by the expected amount of information flow. This effort solicits the development of smart sensor management approaches for optimized sensing in a dynamic, complicated environment characterized as containing many moving targets, performing maneuvers that are intermittently obscured to the sensor. While previous efforts have focused on portions of this problem, this topic seeks approaches that address using multiple sensors for detection, and tracking of multiple targets from single and distributed radar in a closed loop manner. Specifically, we seek approaches to capture the scene probabilistically and use this information to drive future sensing actions, and lead to quantitative improvements in performance over current approaches as measured by standard tracking benchmarks such as time until correct detection and identification, track mean square error, and optimal sub-pattern assignment (OSPA). Ideally, we seek radar resource allocation techniques that incur a weak dependence on the number of sensors and the number of targets. The approach must enable application of ideas from cognitive sensing to guide agile sensor action at the next time step and beyond, such as selection of pointing, mode, waveform [5], and PRF. 

PHASE I: Develop a closed loop sensor management framework for concurrent detection, and tracking of ground targets in a single sensor setting. A host of multi-objective optimization problems encountered in this context, need to be addressed. The approach should scale to large scenes with multiple targets exhibiting tradeoff between detection and tracking functions. Performance analysis and benchmarking of the approach are called for using standard measures. 

PHASE II: Extend the approach developed in Phase I to include distributed radars tracking multiple targets. The resulting optimization problem for resource allocation needs to be treated from an analytical standpoint to ensure that it incurs a weak dependence on the number of sensors and number of targets in a given scenario. Performance validation and comparison with other candidate methods needs to be undertaken with respect to standard metrics. Validation of the concepts developed in the effort need to be undertaken via simulation as well as experimental demonstrations. 

PHASE III: Techniques from this effort will be fundamental to the performance evaluation and benchmarking of closed loop radar detection and tracking. Transition opportunities for this effort include ongoing radar programs within AFRL. Technology insertion opportunities include platforms such as JSTARS and Global Hawk. 

REFERENCES: 

1. S. Haykin, Y. Xue, and P. Setoodeh, “Cognitive Radar: Step Toward Bridging the Gap Between Neuroscience and Engineering”, The Proceedings of the IEEE, vol. 100, no. 11, pp. 3102-3130, Nov. 2012.; 2. N. Goodman, P. Venkata, and M. Neifeld, “Adaptive Waveform Design and Sequential Hypothesis Testing for Target Recognition With Active Sensors”, IEEE Journal of Selected Topics in Signal Processing, vol. 1, no. 1, pp. 105-113, June 2007.; 3. D. Fuhrmann, “Active-Testing Surveillance Systems, or, Playing Twenty Questions with Radar”, in Proc. 11th Annual Adaptive Sensor and Array Processing (ASAP) Workshop, MIT Lincoln Laboratory, Lexington, MA, Mar. 11-13, 2003.; 4. C. Kreucher, A. Hero, K. Kastella, and M. Morelande, “An Information-Based Approach to Sensor Management in Large Dynamic Networks”, The Proceedings of the IEEE, vol. 95, no. 5, pp. 978-999, 2007.

KEYWORDS: Closed Loop Radar, Resource Allocation, Distributed Radar 

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Demonstrate contour, shape, optical-flow, or other image segmentation techniques for robust model based test and evaluation of target attitude determination, using perfect a priori knowledge of target geometry, for arbitrary cluttered backgrounds. 

DESCRIPTION: Photogrammetric multi-view determination of target attitude (or pose) can be a simple machine vision problem, given sufficiently resolved imagery and benign backgrounds. For ground-based imagery of missiles in flight, however, resolution can be marginal and backgrounds are rarely benign. For cooperative tests, the external geometry of the missile can be known a priori to whatever accuracy is desired. Additionally, the location of the target missile can generally be localized in the image a priori as well. This is not a tracking issue. What is needed is an evaluation algorithm that provides the “best” overlay of the known physical target on top of the measured scene. Marginal resolution, varying lighting conditions, cluttered backgrounds, and poor target contrast contribute to the difficulty of segmenting the image, and determining the best monocular pose for the target missile. A significant portion of the effort should involve selecting and or creating relevant bench mark test data sets for comparison against other state of the art approaches and methods. 

PHASE I: The Phase I effort should leverage industrial and academic advances to develop approaches to achieving the desired overlay at various image resolutions, signal to noise levels, clutter, etc. The method should be demonstrated on a variety of government-supplied synthetic and real datasets, as well as others. 

PHASE II: A successful research effort will produce the following deliverables: 1) An image processing toolkit suitable for inclusion in current government-owned analysis tools, 2) A report detailing extensive verification of the toolkit using benchmark synthetic and real imagery, and 3) A paper accepted to a relevant scientific conference. 

PHASE III: The Phase III program would commercialize the Phase II product for applicability to a wide range of image analysis topics, such as target acquisition, tracking, identification, and general pose estimation. 

REFERENCES: 

1. “Spatially variant mixture model for natural image segmentation,” Can Hu, Wentao Fan, Ji-Xiang Du, Nan Xie, SPIE J. Electronic Imaging 26 (4), 11 July 2017; 2. “Automatic Image Registration Based on Shape Features and Multi-scale Image Segmentation, “ Haigang Sui et al., IEEE 2017 2nd International Conference on Multimedia and Image Processing (ICMIP)C. Das, Naresh & Olver, Kim & Towner, F. (2005). High emissive power MWIR LED array. Solid-State Electronics. 49. 1422-1427. 10.1016/j.sse.2005.06.018.; 3. Interactive image segmentation based on object contour feature image,” Qiang Chen et al., 2010 IEEE International Conference on Image Processing, pp. 3605-3608; 4. Spatio-temporal image segmentation using optical flow and clustering algorithm,” S. Galic et al., IWISPA 2000. Proceedings of the First International Workshop on Image and Signal Processing and Analysis. in conjunction with 22nd International Conference o

KEYWORDS: Image Analysis, Image Segmentation, Pose Estimation, Missile Attitude 

TECHNOLOGY AREA(S): Info Systems 

OBJECTIVE: Leverage the latest research developments in NER and related information extraction tasks to better cope with challenging but important noisy user-generated text - “chat” data - based on state of the art deep learning techniques. 

DESCRIPTION: Noisy user-generated text such as that found in social media, web forums, online reviews, twitch chats, etc., are increasingly becoming important sources of information since they tend to reflect real intentions, raw sentiments, unfiltered opinions, secret plans, etc. However, noisy user-generated text presents great challenges to information extraction tasks including Named Entity Recognition (NER) because of its colloquial style of language, improper grammatical structures, spelling inconsistencies, informal abbreviations, slang, emoticons, etc. In addition, such data makes detecting named entities, which forms the basis of information extraction pipelines, difficult because noisy-user generated text often contains rare, unusual, previously-unseen and rapidly-changing emerging entities with unusual surface forms. Recent university and commercial studies have shown that common approaches to information extraction on such data performs very poorly and does not generalize well enough to handle rare and emerging entity types [Augenstein et al., 2017] [Pottenger et al., 2015]. This demonstrates that information extraction, including NER, is still an unsolved task in such data and needs continual research into approaches with better generalization capabilities. To this end, several notable approaches have recently been proposed, which are all based on state of the art deep learning techniques. One of them is the bidirectional LSTM approach proposed by a University of Cambridge research team [Limsopatham et al., 2016], which won first place in the Workshop on Noisy User-generated Text (WNUT) 2016 challenge. Another is based on a multi-task deep neural network approach based on LSTMs, proposed by a team from the University of Houston [Aguilar, G. et al., 2017], which achieved the best performance in WNUT 2017. More recently, breakthroughs in NER are coming from incorporation of neural language models as evidenced by [Tran et al., 2017] [Peters et al., 2017] [Liu et al., 2017]. Deep learning coupled with neural language models exceeds previous performance records by a significant margin and shows promising results. These approaches, however, have not yet been extended to noisy user-generated data and lack consideration of specific properties of such noisy data 

PHASE I: Perform deep study analysis of state of the art deep learning techniques and perform analysis on which one or a combination of approaches provides knowledge capture in the micro-text information space. Obtain baseline measurements that can be used in phase II for development of applications based on feasibility demonstration developed in phase 1. Techniques to be investigated include but are not limited to character-level language models (LM) incorporated into deep neural networks to discover hidden information in character-level irregularities common in noisy user-generated text; LSTM approaches and NER applications. 

PHASE II: Leverage the latest research developments in NER and results from phase I and other related information extraction tasks to better cope with challenging but important noisy user-generated micro-text – like “chat” data – based on state of the art deep learning techniques. Develop an Open Architecture application approach that will provide improved NER and related information extraction performance for noisy social media “chat” text, and at the same time will reduce the requirements of human effort needed to create labeled ground truth. This may be demonstrated because character language models not only encode complexities of language such as grammatical (and lexical) structure, but also distill information available in vast unannotated corpora [Jozefowicz et al., 2016]. 

PHASE III: Develop an application approach that can be employed to satisfy requirements of multiple open architecture implementations such as OA DCGS, ICITE, Apple or Android interfaces. 

REFERENCES: 

1. Aguilar, G. et al., A Multi-task Approach for Named Entity Recognition in Social Media Data, WNUT 2017; 2. Derczynski, L. et al., Results of the WNUT2017 Shared Task on Novel and Emerging Entity Recognition, WNUT 2017; 3. Tran, Q. et al., Named Entity Recognition with stack residual LSTM and trainable bias, arXiv 1706.07598, 2017 4. Liu, L. et al., Empower Sequence Labeling with Task-Aware Neural Language Model, arXiv 1709.04109, 2017; 4. Rafal Jozefowicz et.al, Exploring the Limits of Language Modeling, arXiv 1602.02410, 2016 6. Limsopatham, N. et al., Bidirectional LSTM for Named Entity Recognition in Twitter Messages, WNUT 2016 7. William M. Pottenger, et al., SURREAL Final Report, A

KEYWORDS: Information Extract, Micro-text, Named Entity Recognition, NER, Sentiment Analysis, Noisy Text, User Generated, Long Short Tern Memory (LSTM), Deep Learning, Active Learning 

TECHNOLOGY AREA(S): Info Systems 

OBJECTIVE: Develop the ability to transmit ultra-wideband radio signals from subwavelength antennas on airborne platforms. 

DESCRIPTION: Radio transmission is an important part of information transfer and critical for military operations during both peacetime and conflict. Antennas for radio transmission typically increase in physical size with wavelength but physically small antennas are highly desirable for airborne platforms. As result, classic transmitting antennas become problematic for lower frequencies on airborne platforms. Electrically small antennas can be used but they have very limited bandwidth, large matching and tuning elements and power limitations [1]. Furthermore, it is increasingly desirable to use ultra-wideband signals which can provide high data rate, low probability intercept and anti-jam communications capability. However, with the exception of highly inefficient antennas, ultra-wideband electrically small antennas these are not available with today’s technology. This topic is intended to examine new and innovative techniques for radiating ultra-wideband signals from electrically small antennas on airborne platforms. The limits for classic electrically small antennas are well known and fundamental [1]. However, there are emerging techniques using non-linear or time varying antenna and tuning elements that have the promise of overcoming these limits and thus enable transmission of ultra-wideband signals from electrically small antennas [2, 3, 4, 5]. These techniques use non-linear or time varying antenna elements and/or tuning & matching systems. This emerging technology has the potential to enable the use of small ultra-wideband antennas on airborne platforms with nearly zero cross section. 

PHASE I: The approaches described in the literature for developing ultra-wideband transmitting antennas will be examined and the most promising technique selected. Rigorous modeling, analysis and simulation will be used to develop an understanding of the relationship between the critical parameters for the selected approach. These include but are not limited to the length and shape of the antenna and voltage limits. The availability of non-linear time varying elements will be determined and the relationship of the critical parameters to the desired signal bandwidth will be explored. The objective is to design a demonstration model to validate the approach chosen at low power. This phase will include investigation into the possibility of combining non-linear time varying technology with different shaped antenna elements. 

PHASE II: During this phase a scale model prototype of the ultra-wideband transmitting antenna that would be suitable for use on an airborne platform will be constructed and tested. The frequency band and waveforms of interest will be selected based on Air Force input. The signal formats selected will be transmitted and received during this test. These signals would be received at terrestrial locations for analysis. As part of Phase II, the fundamental limitations for this technology will be explored especially in terms of the transmitting hardware needed to enable this technology for use in various airborne applications. The conclusion will be a recommended way forward for development of this technology. 

PHASE III: The ability to transmit an arbitrary wideband waveform from an electrically small antenna will be extremely useful for many military and civilian applications. During phase III a prototype system will be constructed based on the results of Phase II and tested in laboratory and flight test environments. The design will be refined based on the test outcome and customer feedback. 

REFERENCES: 

1. Hansen, R.C., Electrically Small, Superdirective, and Superconducting Antennas, Wiley, 2006; 2. Yao, Weijun Yuanxun Wang, “Direct antenna modulation - a promise for ultra-wideband (UWB) transmitting”, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535), 6-11 June 2004; 3. R. Janaswamy, Time varying antennas for enhanced bandwidths, 2014 IEEE Antennas and Propagation Society International Symposium, 2014, doi:10.1109.APS.2014.6904641; 4. Daly, E. L., Bernhard, J. T., & Daly, M. P. (2016). Synchronously tuned patch for transmitting FSK. In 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016 - Proceedings (pp. 2147-2148). [7696780] Institute of Electrical an

KEYWORDS: Ultra-Wideband Radio Transmission, Electrically Small Antennas, 

TECHNOLOGY AREA(S): Info Systems 

OBJECTIVE: Develop link, transport and networking layer protocols for wideband wireless networks at THz frequencies (above 100 GHz). 

DESCRIPTION: Terahertz band communications is envisioned to answer today’s increasing demand for higher data rates and relieve congestion in conventional RF spectrum. Large available spectrum in terahertz frequencies can enable new high-bandwidth applications that are not feasible with current narrow- band wireless technologies, such as secure airborne communications and in-air sensor data sharing among networks of unmanned autonomous systems. The focus of this research is to develop novel link, transport and network layer solutions that will exploit the full potential of unprecedentedly large bandwidth offered by extremely high-frequency bands. Traditionally, wireless network protocols have been designed with the major constraint being available bandwidth. We are interested in new and novel protocols at link, transport and network layers that do not hold the same assumption but address the challenges stemming from the characteristics of terahertz band. For example, very high path loss caused by atmospheric and molecular absorption at these frequencies calls for the use of highly directional antennas and/or large antenna arrays to focus the beam energy to an intended direction. These directional links as well as beam blockage due to very short wavelengths impose challenges on current medium access strategies that relies on omnidirectional broadcast of control messages. Moreover, in wideband communications systems where tens of Gigabit of data can arrive in a second, the overflow of routing nodes needs to be prevented and fundamentally new routing strategies are required to support ultra-wideband networks. In short, we need link and above protocols to support wideband (10 Gbps and above) communications with intermittent link connectivity (order of seconds or less) due to absorption and blockage, etc. In particular, we are interested in strategies and protocols for dynamic beamforming, beam tracking and alternate path finding in case of beam blockage, in-band and out-of-band link layer protocols, active and passive relaying and multi-hop communication schemes for robust signaling, transport and network layer protocols that can support very high data arrival rates without data loss or queueing issues, synchronization and medium access strategies that consider the effect of very high-speed data rates (tens of Gbps or at least multi-Gbps) in dynamic airborne networks. 

PHASE I: Phase 1 will design algorithms and protocols in link layer and above to support wideband networks in terahertz frequencies and modeling and simulation results should be demonstrated via an appropriate discrete event simulator. The final report should also describe a potential live-demonstration test set up and methodology. 

PHASE II: Phase 2 will develop a prototype system that implements the protocols and validates the results from phase I. A small-scale live-demonstration as well as testing of the algorithms in a relevant environment is expected. Phase 2 should include delivery of software and on-site support for testing. 

PHASE III: Military systems would benefit from both a significant increase in available air to air communications capacity for ISR applications. Developed protocols and strategies will enable wideband communications links to be incorporated into existing airborne networks across many Air Force platforms. Commercial Applications: As new wireless services like 5G are realized, there is an increased market for high frequency devices to help drive the commercial wireless market. The deployment of new wireless network designs incorporating technologies like microcells make consideration of high frequency networks realizable. 

REFERENCES: 

1. T. Kurner and S. Priebe, “Towards THz Communications- Status in Research, Standardization and Regulation,” Journal of Infrared, Millimeter, and Terahertz Waves, vol. 35, no. 1, pp. 53–62, 2014.; 2. I. F. Akyildiz, J. M. Jornet, and C. Han, “Terahertz band: Next frontier for wireless communications,” Physical Communication (Elsevier) Journal , vol. 12, pp. 16–32, Sep. 2014.; 3. J. F. Federici, J. Ma, and L. Moeller, “Review of weather impact on outdoor terahertz wireless communication links,” Nano Communication Networks, vol. 10, pp. 13–26, 2016.; 4. H.-J. Song and T. Nagatsuma, “Present and future of terahertz communications,” IEEE Transactions on Terahertz Science and Technology, vol. 1, no. 1, pp. 256–263, 2011.

KEYWORDS: Wideband, Networking, Terahertz, Medium Access, Link Layer, Transport Layer 

TECHNOLOGY AREA(S): Info Systems 

OBJECTIVE: Develop cost-effective modules or antennas that will enhance the spectral agility of legacy radios through multi-band operation. 

DESCRIPTION: Current tactical data links such as Link 16, Tactical Targeting Network Technology (TTNT), Tactical Common Data Link (TCDL), Multi-Function Advanced Data Link (MADL), etc. each require a dedicated set of radio frequency amplifiers, filters, and antennas, which negatively contribute to the size, weight, and power (SWaP) of airborne platforms. Supporting multiple unique systems is particularly difficult on space-constrained unmanned aerial systems (UAS) and tactical platforms. Programs such as the Battlefield Aerial Communications Node (BACN) payload have had success in bridging the gap between these various data link types, and other Air Force developments are investigating the advantages of directional data links for spectrum re-use and reduced probability of intercept. Extending both concepts such that the multi-band/multi-waveform gateway includes spatial directionality can provide additional cost and SWaP savings while enhancing connectivity. The spectral and spatial agility provided by such a system will also have benefits for mitigating friendly RF congestion and adversary jamming. Systems will be required that include low SWaP multiband RF electronics and antennas, as well as resource management techniques to efficiently utilize systems capable of simultaneous frequency and spatial diversity. The MESA antenna system should support airborne data links at 10-45Mbps and ranges of 100-300nmi. 

PHASE I: Phase I will study candidate designs for multi-band modules/antennas and their performance and anticipated size, weight, and power - cost (SWaP-C) for different con-ops. Phase I results should quantify the benefits of different approaches for varying link distances, interference levels, and scintillation environments using analysis and/or simulations, accounting for practical implementation constraints. Work with the government to identify the requirements for a Phase II demonstration. 

PHASE II: Implement the selected technology in hardware and demonstrate the gains at an AFRL test range. Present a path toward optimizing SWAP-C. Show compatibility among demonstrator systems and legacy (in-use systems) radios. 

PHASE III: Develop and deliver flight-qualified units with a complete RF system for transition to appropriate platforms. The product could be used in a variety of homeland security areas, such as border patrol and the Coast Guard. 

REFERENCES: 

1. T.F. Brukiewa et al, “Demonstration of an X/Ku band multi-link antenna system for CDL communications”, 2003 IEEE International Symposium on Phased Array Systems and Technology, 14-17 October 2003, Boston MA.; 2. B. Trent et al, “DYNAMICS: Inverse mission planning for dedicated aerial communications platforms”, 2015 IEEE Military Communications Conference, 26-28 October 2015, Tampa FL; 3. G. Wang et al, “A novel MAC protocol for wireless network using multi-beam directional antennas”, 2017 International Conference on Computing, Networking and Communications, 26-29 January 2017, Santa Clara CA

KEYWORDS: Multiband, Spectrum Agility, MIMO, Airborne Networking, Software Defined Radio 

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Design and develop a methodology, framework and tool to assess, simplify and automate cybersecurity controls and reporting 

DESCRIPTION: The DOD has moved to the Risk Management Framework (RMF) to manage the cyber posture of aircraft platforms. As a part of the RMF process, each platform must complete an analysis of cyber controls to be documented in the Security Controls Traceability Matrix (SCTM). The basis for the controls is in the National Institute of Standards and Technology (NIST) Publication 800-53 Security and Privacy Controls for Federal Information Systems and Organizations. AFLCMC has documented a subset of the NIST controls applicable to an aircraft platform, referred to as the aircraft overlay, as well as a set of controls that provide cyber resilience, referred to as the cyber resiliency controls. Many of the controls are organizationally–based and may be governed by DOD and/or Air Force (AF) Instructions, guidance, handbooks, and operating instructions. Evidence of implementation of NIST controls should then be documented by unit self-inspection results contained in the Management Internal Control Toolset (MICT) and/or inspection data contained in the Inspector General Evaluation Management System (IGEMS). MICT is a web-based and real-time automated self-assessment (SA) program for accessing SA checklist from the repository within MICT. IGEMS is a web-based software program serving as an inspection tool comprised of planning, executing, reporting, and corrective action management. In addition, the NIST controls are based on an enterprise information technology system and do not lend themselves to be understood by aircraft operators and maintainers. The goal of this STTR Topic is to create a tool to simplify and automate security controls analysis and reporting. The tool and framework must mine the data from different DoD and AF Instructions, Guidance, and Operating Instructions to establish mapping between NIST controls and governing instructions which then can support verification of implementation, compliance, and effectiveness of the controls by searching through MICT and IGEMS, and other identified sources. The tool will analyze and determine which portions of the identified sources are related and match to the appropriate NIST controls. The language analyzing portion of the tool would allow verification of implementation and compliance via MICT or IGEMS. The tool would guide the users with platform-applicable questions to determine a control’s applicability to implement for the aircraft overlay and cyber resiliency controls. Based upon the user’s responses, the tool would tailor the applicable cybersecurity controls. The tool will maintain access to repositories of controls, correlated data, and questions. The tool would allow changes, updates and import of new data, controls, and questions. The tool would populate the results into a SCTM template. A sample of pre-determined documents will be identified by the Government that meet the criteria and would normally be selected if going through the process manually. The tool’s ability to also select this sample of documents will be the gauge of accuracy. Furthermore, a sample of the controls selected by the tool will be manually checked for accuracy. The metric for evaluating proposed framework and tool is 80% accuracy of selecting the set of sample documents and security controls for aircrafts. 

PHASE I: Design a methodology, framework and tool to mine data from different DoD and AF Instructions, Guidance, Operating Instructions and MICT, to determine their applicability to aircraft overlay and cyber resiliency, maintain the database for cybersecurity controls and questions and populate the results to SCTM template. Provide a proof-of-concept design and methodology to demonstrate the feasibility of the proposed tool and framework. 

PHASE II: Based on the result from Phase I, refine and extend the prototype system design to a toolset that could assess, simplify, and automate cybersecurity controls and reporting by mining different Air Force or DoD instructions, and operating instructions and guidance. Demonstrate the capability, effectiveness and usability of the framework and tool. 

PHASE III: The proposed methodology, framework and tool should be enhanced to automate and simplify cybersecurity controls and reporting for both military and commercial applications. The tool can be used to track rapidly changing Risk Management Framework guidance. The tool can be used to track rapidly changing commercial guidance and policies. 

REFERENCES: 

1. NIST Publication 800-53 - Security and Privacy Controls for Federal Information Systems and Organizations https://csrc.nist.gov/publications/detail/sp/800-53/rev-5/draft; 2. Management Internal Control Toolset (MICT) https://www.dau.mil/cop/bes/Pages/Topics/Unit%20Self-Assessment%20Program%20USAP.aspx; 3. Inspector General Evaluation Management System (IGEMS) https://static.e-publishing.af.mil/production/1/saf_ig/publication/afi90-201/afi90-201.pdf; 4. NIST SP 800-37 Rev. 2 - A System Life Cycle Approach for Security and Privacy https://csrc.nist.gov/publications/detail/sp/800-37/rev-2/final

KEYWORDS: Security, Cyber, Risk Management Framework, Tool 

TECHNOLOGY AREA(S): Info Systems 

OBJECTIVE: Develop a capability to evolve and generate malware test samples for automated malicious feature extraction to support cyber-attack immunity for embedded systems 

DESCRIPTION: The ability to detect targeted cyber-attacks against military weapon systems and to quantitatively measure the effectiveness of cyber security solutions remains an unsolved problem. One reason for this is the lack of relevant malware samples that target the embedded system of interest to the Air Force, namely avionics and sensor systems. The lack of an embedded system malware repository impacts our ability to both develop malware detection algorithms for these platform as well as test existing cyber security solutions against malware payloads that could in principle be created by our adversaries. The root cause of the problem is the fact that the effectiveness of cyber security solutions is a function of the adversary’s knowledge about the security flaws in the system, their ability to gain access to those flaws, and their ability to exploit those flaws [1], which is often unknown to the developers of the protection solutions. While red teaming is often used as a means to measure the effectiveness of cyber solutions, these exercises are limited in scope and by the knowledge, skills, and resources of the red team, which do not necessarily reflect a determined nation-state adversary in a war-time scenario. The lack of quantitative measures of effectiveness is exacerbated by the fact that flaws may exist on the system that are unknown to the cyber protection developers and their red teams that could be uncovered and exploited by real adversaries. What is required is the ability to objectively simulate the attack creation process of our cyber adversaries and to proactively develop malware detection solutions in anticipation of those threats [2]. The goal of this topic is to use malware samples that have been automatically generated [2] to create a co-evolving protection system that can detect, respond, and adapt to unforeseen threats. In particular, focus should be given to detecting and responding to malware that has been surreptitiously embedded in legitimate avionics/ISR software and firmware. A co-evolutionary protection architecture would result in the capability to quantitatively test existing malware detection algorithms with novel malware samples in advance of a real-world attack, as well as to extract distinguishing malicious patterns that can be used as part of a cyber immune system [3]. While not foolproof, immune system-like protections for avionics and ISR-based embedded systems would be game-changing with respect to existing cyber security solutions and would provide measures of effectiveness for other cyber security products. The above approach requires innovative research and development of evolvable malware that targets an embedded system and an ability to evaluate the effectiveness of those malware samples, whether through instantiation on actual hardware or through software simulation. For the purpose of this topic, suggested target platforms include, but are not limited to, small unmanned aerial vehicles (sUAV) or representative embedded system components that might be found in an avionics or intelligence, surveillance, reconnaissance (ISR) system. The ultimate goal is to create an ability to detect malware that has been embedded within legitimate software or firmware that is critical to the operation of the embedded system. 

PHASE I: Develop an approach, architecture and limited-scope prototype that demonstrates the ability to evolve malware samples that targets embedded system software or firmware. These malware samples should be undetectable by at least one commonly used commercial off-the-shelf anti-virus program. Malicious features that are differentiable from the host software should be identified. 

PHASE II: Expand the quantity of malware test samples generated, categorize the classes of attacks, and automate the malicious feature extraction process for use in the cyber immune system. Demonstrate the ability to distinguish malicious features from the targeted software or firmware. Determine the false positive and false negative rates of detection of the cyber immune system. 

PHASE III: The final product will have both commercial and military avionics system applications, as well as a broad class of embedded system applications, including Supervisory, Control, and Data Acquisition (SCADA) and Industrial Control Systems (ICS). 

REFERENCES: 

1. Jeff Hughes and George Cybenko, “Three Tenets for Secure Cyber-Physical System Design and Assessment,” Proc. of SPIE Vol. 9097, 9097A, 18 June 2014.; 2. Sadia Norren, Shafaq Muraza, M. Zubair Shafiq, and Muddassar Farooq, “Evolvable Malware,” Proceedings of the 11th Annual conference on Genetic and evolutionary computation (GECCO), Montreal, Quebec, Canada, 2009.; 3. Mohammad M. Masud, Latifur Khan, and Bhavani Thuraisingham, “A scalable multi-level feature extraction technique to detect malicious executables,” Information System Frontiers, 10(1): 33-45, March 2008.

KEYWORDS: Evolutionary Computing, Genetic Algorithms, Malware Detection, Embedded System Security, Avionics Cyber Security 

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Develop and demonstrate experimental techniques to reproduce complex flow fields determined by Computational Fluid Dynamics (CFD) solutions of integrated vehicle/inlet configurations for use in direct connect testing of supersonic inlets. 

DESCRIPTION: The Air Force Research Laboratory’s Aerospace Vehicles Division (AFRL/RQV) wishes to break the problem of analyzing modern supersonic external compression inlets (such as inlets on the F-15) into three distinct steps, 1) simulating the flow entering the inlet, including the forebody effect and forward portion of the inlet, especially at angles of attack and yaw, using CFD, 2) using the predicted CFD flowfield just upstream of the terminal normal shock inside the inlet, and mimicking this flow just upstream of the shock using a variety of physical techniques (blowing, suction, wall shaping, etc) inside of a duct, and then 3) simulating the rest of the inlet and diffuser conventionally, in a direct connect rig. AFRL is essentially looking for innovative ways of simulating the distorted flow ingested in inlets at angle of attack or yaw (pressure distortion and swirl) in a direct connect rig, without having to test the actual forebody and inlet front end. This would allow for the inexpensive study of inlets at off design, at smaller scale, and reduced cost. In the direct connect rig being considered at AFRL, it is envisioned that the desired pressure/swirl distortion pattern would be evaluated before the simulated cowl lip, but the flow control used to create the pattern can be contained anywhere between the beginning of a bellmouth to accelerate the inflow, to the constant area section behind the converging/diverging nozzle. Being able to accurately reproduce these distorted flow fields in both pressure distortion intensity and location, as well as, swirl intensity, location and direction in the intended rig would allow experimental measurements of the highly viscous flow field of a complete inlet design. The measurements at the end of the diffuser have historically been very difficult to simulate computationally and expensive to determine experimentally. The combination of robust computational predictions upstream of the terminal shock of a full size aircraft, the technologies created in this effort, and experimental measurements downstream of the terminal shock will allow RQV to simulate a range of maneuver conditions for future aircraft. This experimental data is critical to determine installed performance parameters at key flight points in a relatively low cost, rapid turnaround test rig as compared to prohibitively expensive (10 ft. to 16 ft.) wind tunnel facilities. Historically, pressure/swirl distortions have been generated using multiple techniques including screens, jets, vanes, and bellmouth designs. For screens, wire size and screen density were chosen using prior experience developed in a proprietary manner. Another method was to use air jets where the pressure of the jet was individually adjusted based upon the required distortion. Swirl has been generated in various ways but recently has used aerodynamic vanes. A rapid turnaround system that can produce distortion generation at low cost is desired. It is preferred that firms avoid extensive research into how each individual distortion generation device should be arranged to accomplish the desired flow profile goals. Distortion generation performance just prior to the simulated cowl will be validated. Another change from historical testing would be the change in internal flow path shape. As shown in SAE 1419, typical screens/jets/vanes are done on relatively large axis-symmetric shapes at subsonic Mach numbers. In contrast, the shape of ADAC diffuser will be a much smaller rectangular cross section (4.21x6 inches near terminal shock) and the intended flow field where the distortion is needed will be supersonic. 

PHASE I: Design/develop a range of techniques to provide arbitrary supersonic flow fields. Fundamental patterns will be provided to replicate. Using computational techniques and/or lab testing, the most promising techniques will be selected. 

PHASE II: Further refine technology for generating arbitrary supersonic flow fields. Design/develop hardware for generating a specific flow field for use in AFRL ADAC rig. Document performance of system through flow field measurements. In order to perform proof of concept test program, offerors may request use of the ADAC test rig (subject to availability) located at Wright-Patterson AFB. Only U.S. Citizens will be permitted to work within AFRL Facilities. 

PHASE III: Develop refined system and methodology for generating a range of supersonic flow fields typical of both military and commercial vehicle supersonic inlet systems. System should be capable of being used in DOD, NASA and commercial aircraft company test facilities. 

REFERENCES: 

1. Advisory Group for Aerospace Research and Development. Aerodynamics of Power Plant Installation Part 1, AGARDograph 103. AGARD, 1965. http://www.dtic.mil/dtic/tr/fulltext/u2/656569.pdf; 2. J. Koncsek, "An Approach to Conformal Inlet Diffuser Design for Integrated Propulsion Systems", 17th Joint Propulsion Conference, Joint Propulsion Conferences. https://doi.org/10.2514/6.1981-1395; 3. D. Beale, S. Wieland, J. Reed, and L. Wilhite, "Demonstration of a Transient Total Pressure Distortion Generator for Simulating Aircraft Inlet Distortion in Turbine Engine Ground Tests", ASME Turbo Expo 2007: Power for Land, Sea, and Air, Vol. 1, pp. 39-50.; 4. SAE International, "Inlet Total-Pressure-Distortion Considerations For Gas-Turbine Engines AIR 1419C", 2017.

KEYWORDS: Flow Distortion, Intake Aerodynamics, Pressure Distortion, Propulsion Integration, Direct-connect 

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Develop a rapid and easy to use lower order computational fluid dynamics method to analyze the aerodynamic performance, stability, and control of air vehicles in order to aid design, simulation, and technology assessment. 

DESCRIPTION: AFRL’s Aerodynamic Technology branch is tasked with discovering, developing, and demonstrating aerodynamic technologies for war-winning capabilities for the USAF. A range of technical activities including configuration aerodynamics, flow control device development, high fidelity computational tool development and application, and wind tunnel testing must be conducted to reach these goals. The accessibility of multi-core computers, Reynolds Averaged Navier Stokes codes, and aircraft geometry modeling tools has made the use of high fidelity CFD much more common; however, the time required for computational execution and processing 'touch' labor by the engineer is still much greater for RANS analyses compared to lower order methods. While some flow regimes require higher fidelity, often a reduced order method can suitably model vehicle aerodynamics and speed up design or analysis processes. These lower order methods offer attractive tradeoffs between computational solution time and accuracy, and with modern software approaches, numerical schemes, and other simulation techniques, be beneficial for use in early aerodynamic predictions and design. While using reduced order physics equations to compute accurate, detailed pressure fields on and off the vehicle body efficiently, geometry is still represented in full 3D definition. These results can identify drag contributors, develop structural loads, and compute stability and control derivatives, and serve a host of other aeronautical engineering purposes. Once a vehicle has been designed by a lower order method, it can be passed along to Euler or RANS methods to develop the design further (as necessary). Though potential methods have been in use for 50 years, they remain key tools in today's multi-fidelity aerodynamic analysis environment. However, there is much that can be leveraged from recent software, numerical, and computational hardware advances to improve ease-of-use, speed, and accuracy of reduced order methods. Desired attributes of a modern lower order aero tool include ease-of-use, speed, and accuracy. Additional considerations and capabilities are necessary so the code is compatible with today's analysis processes. Ease-of-use: the tool should be able to: be used on multiple OSs; take unordered quad panel or triangulated surface meshes as input; not require specification of wake geometry; be equipped with a GUI geometry viewer to aid in setup and processing of the analysis; be compatible with a variety of input formats. Speed: the tool should: use modern numerical techniques to rapidly and efficiently solve large mesh solutions; utilize a specifiable number of processors; offer ease-of-use attributes to reduce 'hands on' time required to setup the cases and post-process the results - in doing so, overall end-to-end solution time is reduced. Accuracy: the tool should be able to: handle suitably large, dense surface meshes; handle multi-body meshes; model propulsion related aerodynamic effects; deform/relax the wake mesh to capture vortex and wake effects; estimate viscous drag by way of on-body streamline tracing or strip-wise computations; estimate or correct for compressibility effects, as appropriate. 

PHASE I: Demonstrate the feasibility of the proposed analysis tool to easily and quickly evaluate aerodynamic performance. Initial system architecture and proposed interfaces will be defined, and core algorithms prototyped. An alpha version of the tool should be produced (not full featured). 

PHASE II: Continued development of the tool, to include implementation and refinement of the core features, and the user interface and viewer. Iterative beta releases should be delivered as tool matures. Draft user's manual and theory document should be produced. Validation of aerodynamic results against trusted data to be shown. Sample integration with CAD/geometry tool derived inputs and shape design code. Exercise of all required features. Maturing commercialization plan. 

PHASE III: Continued refinement of the tool, to include support for multiple operating systems, licensing schemes, and expanding interface to aid in speed and ease of use. 

REFERENCES: 

1. Willis, D., Peraire, J., and White, J., "A Combined pFFT - Multipole Tree Code, Unsteady Panel Method with Vortex Particle Wakes", AIAA-2005-0854; 2005.; 2. P. A., Henne (editor); "Applied Computational Aerodynamics – Progress in Astronautics and Aeronautics", Volume 125 - AIAA; 1990.; 3. Calabretta J., and McDonald R., "A Three Dimensional Vortex Particle Panel Method for Modeling Propulsion Airframe Interaction", AIAA-2010-0679; 2010.; 4. Willis, D., "Enriched Basis Functions for Automatically Handling Wake-Body Intersections in Source-Doublet-Potential Panel Methods", AIAA-2012-0265; 2012.

KEYWORDS: Lower Order CFD, Potential Method, Panel Method, Aerodynamics, Software Development, Fast Fourier Transform, Subsonic Vehicle Design, Aerodynamic Design, Propulsion Integration 

TECHNOLOGY AREA(S): Space Platforms 

OBJECTIVE: Capability to extend current component lifetimes and efficiency performance of existing electric thrusters. 

DESCRIPTION: Helicon plasma thrusters have several potential advantages compared to conventional electric propulsion devices. Future systems must be able to operate continuously for 5 years. For example, spacecraft which are designed to continuously thrust to maintain their orbit, such as a “polesitter” orbit, will need these continuous operations capabilities. Helicon thrusters are electrodeless and therefore do not have issues that devices such as Hall thrusters have that rely on cathodes that corrodes with use. Current helicon devices are experimental. They have been demonstrated in laboratory settings where space flight issues such as mass and size are secondary considerations. Magnets considered for plasma confinement range from permanent to superconducting magnets. The mass and size of these magnets, and the overall helicon device, is a primary issue which will determine their future potential for space propulsion. 

PHASE I: Provide analysis describing the physical principles limiting current helicon designs with a focus on long lived and high power electric propulsion thrusters. Investigate the relationship between thrust and mass, and thrust and size, and particularly assess the thrust to power ratio of different classes of helicon plasma thrusters. Propose a concept to produce a thruster with the size, mass, and packaging that can fly on a spacecraft. Design and select components for a prototype for a satellite application. Provide evidence of the TRL at the beginning and the improvement in TRL after completion of a Phase II prototype. 

PHASE II: Deliver a complete design of a thruster prototype for flight opportunities, the deliverable shall be a design for a thruster prototype that can execute a test sequence over a long duration mission. The primary demonstration will be to use this deliverable to show improved size, mass, and power efficiency. It shall need to be instrumented for long duration testing. Preference shall be given to designs with form factors that are compact for space flight. 

PHASE III: The goal of Phase III is to build and fly in space the prototype thruster designed in Phase II, possibly via the DoD Space Test Program or Advanced Systems Development and Prototyping organization flight opportunities. The helicon plasma thruster technology can be used at all orbits and coupled with their long design life for in-space applications, spacecraft can use this technology to operate on their own for extended periods. Hence all systems, commercial, civil and defense can use a long-lived helicon propulsion solution. 

REFERENCES: 

1. K.Takahashi, et al., “Performance improvement of a permanent magnet helicon plasma thruster”, J. Phys. D: Appl. Phys. 46 352001, 2013.; 2. D.Pavarin, “Feasibility study of medium power helicon thruster”, AIAA, 2008.; 3. C. Charles and R.W. Boswell, "Laboratory evidence of a supersonic ion beam generated by a current-free "helicon" double-layer". Phys. Plasmas 11, 1706-1714, 2006.; 4. M.A. Raadu, 'The physics of double layers and their role in astrophysics', Physics Reports 178, 25-97, 1989.

KEYWORDS: Helicon, Plasma, Continuous Burn Maneuvers, Polesitter, High Power Solar Electric Propulsion 

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Develop Chemical Vapor Deposition (CVD) techniques using novel chemistries for epitaxial growth of 4H-SiC that allow lower than state-of-the-art growth temperatures while retaining state-of-the-art growth rates and improved material quality. 

DESCRIPTION: In recent years, silicon carbide has proven its worth in the power electronics industry. High performance diodes and transistors are commercially available and are being designed into power conditioning systems from a wide range of industries. Transistors can be purchased with voltage ratings up to 1700 V while diodes are available up to 8 kV. Discrete 1200 V diodes and transistors are available with current ratings over 100 A. The low on-resistance, fast switching, high current density, and temperature tolerance provide significant system benefits over silicon devices. These system benefits often outweigh the higher cost of the SiC devices as compared to silicon. While the cost per amp of SiC continues to drop, the cost of SiC bulk material and epitaxy will never be as low as silicon due to the high temperatures and manufacturing methods required to produce SiC. For instance, Si epitaxy is typically grown at temperatures ranging from 1000 to 1200 degrees C with growth rates of hundreds of µm/min. SiC epi, however, is grown from 1500 to 1800 degrees C and, while growth rates above 100 µm/hr are possible, they are challenging to the system and material quality [1]. Because of this, epi cost and throughput remains a cost driver even for 1200 V devices with relatively thin epilayers (~10 µm). For even higher voltage devices (10s of kV) epilayer thicknesses quickly grow to over 100 µm. The challenge of growing thick layers while keeping growth rates and material quality high increase the costs dramatically. The addition of HCl or chlorinated silicon precursors such as chlorosilanes (SiHCl3 and SiCl4) has mitigated some of the deleterious side effects of pushing growth rate such as the formation of silicon droplets on the wafer or other surfaces in the reactor [1]. In addition to providing Cl, chlorinated precursors also appear to provide beneficial surface kinetics that benefit material quality and allow for lower growth temperatures. Chlorinated carbon precursors, chloromethane (CH3Cl) in particular, have been shown to produce high quality films as at growth temperatures as low as 1300 degrees C [1][4]. Growth with chloromethane and chloromethane with HCl or chlorosilane has been shown to be more efficient than growth with hydrocarbons and HCl or chlorosilane alone [1]. Low temperature growth with CH3Cl and SiCl4 was also shown to produce very low donor concentrations (~3e14 1/cm³) in films as thin as 5 µm [2], and much higher than typical acceptor concentrations of over 2e20 1/cm³ [3]. Low temperature growth also has the benefit of allowing for selective area growth using an SiO2 mask [1]. Another area that needs to be investigated is the benefits of CH3Cl/SiCl4 growth on extremely low off-angle or on-axis substrates. Growth rates at 1300 degrees C using CH3Cl have not been shown to equal those of other precursors at much higher temperatures. However, the growth rate possible using CH3Cl/SiCl4 will increase with temperature and could possibly match the rate of other chemistries at still a much lower temperature. Even a more modest reduction in temperature of 100 degrees C could have a significant impact on tool life and throughput. The goal of this effort is to develop a production worthy 4H-SiC epitaxial growth process using chlorinated carbon precursors or other novel precursors with reduced growth temperature and improved material quality as compared to state-of-the-art. 

PHASE I: Exhibit homoepitaxial growth of 4H-SiC using precursors including chlorinated carbon sources or other novel gases with similar effect. Demonstrate growth rates ≥ 20 µm/hr with an ultimate goal of 50 µm/hr while maintaining good quality. Growth temperatures should be at least 100 degrees C less than state-of-the-art for similar growth rates. The n-type dopant concentration and uniformity as well as defect densities should be characterized through appropriate techniques. 

PHASE II: Further develop process to find the optimal balance between growth rate and temperature to maximize benefits to overall device production. Include considerations for thinner (up to 20 µm) and thick (> 100 µm) epi products, including heat up time, cool down time, growth time, material quality, and energy budget. Demonstrate process by growth of lightly doped 100 µm thick n-type epitaxy on whole wafers up to 100 mm in diameter. Perform industry benchmark characterization of the material including carrier lifetimes and defect densities. Also demonstrate p-type doping capability. 

PHASE III: DUAL USE COMMERCIALIZATION: Military Application: Power control and distribution of more-electric aircraft, hybrid electric ground vehicles, and directed- energy weapons. Commercial Application: Renewable energy harvesting, hybrid electric vehicles, commercial more electric aircraft, etc. 

REFERENCES: 

1. H. Pedersen, S. Leone, O. Kordina, A. Henry, S. Nishizawa, Y. Koshka, and E. Janzén, “Chloride-Based CVD Growth of Silicon Carbide for Electronic Applications,” Chemical Reviews 2012 112 (4), pp. 2434-2453.; 2. S. P. Kotamraju, B. Krishnan, F. Beyer, A. Henry, O. Kordina, E. Janzén, and Y. Koshka, "Electrical and Optical Properties of High-Purity Epilayers Grown by the Low-Temperature Chloro-Carbon Growth Method," Materials Science Forum, 2012 717-720, pp. 129-132.; 3. B. Krishnan, S. P. Kotamraju, G. Melnychuk, H. Das, J. N. Merrett, and Y. Koshka, “Heavily Aluminum-Doped Epitaxial Layers for Ohmic Contact Formation to p-Type 4H-SiC Produced by Low-Temperature Homoepitaxial Growth,” Journal of Elec Materi 2010 39 (1) pp. 34-38.; 4. Y. Koshka, “Method for Epitaxial Growth of Silicon Carbide,” US Pat No. 7,404,858 (July 29, 2008).

KEYWORDS: Silicon Carbide, Epitaxy, 4H-SiC, Semiconductor 

TECHNOLOGY AREA(S): Bio Medical 

OBJECTIVE: Under this STTR, performers shall develop a prototype real-time, portable, ruggedized functional near-infrared spectroscopy (fNIRS) system capable of performing mission readiness and fitness for duty assessments by identifying neurobiological (i.e., psychological and physiological) contributors to human performance in dynamic environments (e.g., aviation). 

DESCRIPTION: Functional near-infrared spectroscopy (fNIRS) is a relatively new method for recording human brain activity while performing various tasks. Traditional approaches to assess neural activity include the electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI), however, these systems offer limited utility in dynamic environments. For example, EEG provides a low spatial resolution for identifying active brain regions and requires a specialized testing environment (e.g., Faraday cages) to reduce ambient electromagnetic noise. While fMRI typically provides good spatial resolution, it can lack temporal resolution due to the latency between task and the corresponding blood-oxygen-level dependent signal, and the system is typically large and immobile. In contrast, fNIRS overcomes the issues of brain region specificity and timing, and provides ample application in dynamic environments due to its portability and rapid sampling rate. Additionally, fNIRS is a reliable tool for assessing various physiological states, such as levels of hypoxia and dehydration (via blood volume), and psychological states, such as attentiveness, workload, and fatigue (Afergan et al., 2014; Ferrari & Quaresima, 2012). When a person reaches mastery (i.e., automaticity) in a specific motor task, brain activity changes within the corticostriatal and corticocerebellar pathways depending on which type of motor task is being learned (Doyon et al, 2002; Raley et al., 2004). This well-established understanding of brain activity during a motor learning task is extensible to complex motor tasks (e.g., piloting an aircraft). The variation in activity found during a motor learning task could provide a novel neurobiological signature to assess mission readiness in individuals and teams. With regards to mission readiness, fNIRS could be used to monitor warfighters during the mission preparation process. Information regarding individual or team cognitive states could augment individuals’ performance by providing real-time feedback about brain activity (i.e., neurofeedback). In cases where simulation environments are utilized as part of mission prep, a simulator system could use fNIRS data to modulate training difficulty by generating external cues to mitigate cognitive deficits or take advantage of cognitive resource surpluses (i.e., augmented cognition) (Raley et al., 2004). Moreover, when executing large operations where team cohesion is a top priority, fNIRS can be used to simultaneously scan all team members to assess the synchrony of brain activity (aka hyperscanning). Research suggests that as inter-brain synchrony increases, performance on tasks requiring cooperation or interaction increases as well (Cui et al., 2012). Finally, in the case of individuals recovering from serious bodily injuries, fNIRS can be a powerful tool for motor rehabilitation tasks (Oh et al., 2018). For example, equipment such as treadmills or powered physical augmentation suits (i.e., exoskeletons) could monitor fNIRS data about cognitive state and present more or less challenging regimes for re-learning mobility tasks (e.g., walking, running, balancing). The key problems to address are as follows: • Identify the functional neurobiological parameters for mission readiness and fit-for-duty assessment • Validate that fNIRS can be used to asses and report on these neurobiological states • Determine the changes in cortical activity while learning a complex motor task (e.g., piloting an aircraft) • Validate that fNIRs can be used efficiently to assess mission readiness using cortical activity measures • Deliver a prototype fNIRS system that can integrate into current warfighter equipment and provide assessments of readiness and fitness-for-duty The system should 1) be able to integrate with existing warfighter equipment without interfering with function or safety, and 2) provide an fNIRS assessment of current user state and provide feedback to facilitate mission success. The goals will likely transform as the project progresses to maximize the utility of this investigation. 

PHASE I: During Phase I, performers have three key tasks. First, to derive and validate a set of physiological and psychological states relevant to assessing mission readiness that can be monitored with fNIRS technology. Second, to conceptualize and design a rugged, portable solution to integrate fNIRS with current warfighter equipment. Third, to develop an IRB-approved experimental protocol (to be executed during Phase II) that will provide a usefulness evaluation of the prototype fNIRS solution with respect to assessing mission readiness. 

PHASE II: During Phase II, performers shall complete development of the prototype fNIRS system designed during Phase I and execute the experimental procedure developed in Phase I. Performers shall evaluate the use of fNIRS technology in assessing warfighter mission readiness and provide detailed use cases that can be further investigated prior to transition. 

PHASE III: Refine prototype (based on test and evaluation data from Phase II) to final configuration. Develop manufacturing and logistics process with Department of Defense and other government manufacturing engineers and logisticians. Possible testing of system and mission evaluation at one or more of the locations listed in the next paragraph. In addition, there are several potential civilian use cases for this system such as 1) in police/first responder training: a hyperscanning system could be used during VR training to assess trainee understanding of complex scenarios and a neurofeedback system would provide trainees with feedback to their own perception of the same scenarios; 2) disaster relief: a ruggedized and miniaturized fNIRS system would provide an additional metric for neurological assessment in a disaster area and allow medical personnel to triage based on the system information; and 3) strenuous underwater work: personnel who depend on a closed system to provide oxygen while performing complex motor tasks (e.g., undersea salvage, search and rescue, and undersea cable- and/or pipe-laying and repair) could benefit from a neurofeedback system. This system should serve multiple uses: hypoxia and other physiological state detection; psychological state and readiness for learning; augmented cognition; and social interaction facilitation. Hypoxia research remains the top Naval Aviation safety concern, but recent research suggests other physiological factors may contribute to pilot and aircrew physiological events and be misdiagnosed as hypoxia. This system would be useful in parsing apart these physiological event types. The additional areas of research for this project would be invaluable to aviation training commands across the DOD. Potential government customers include Naval Air Systems Command (NAVAIR), National Aeronautics and Space Administration (NASA), Special Operations Forces Acquisition Technology and Logistics (SOF AT&L), Air Force Research Laboratory (AFRL), Army Research Laboratory (ARL), Office of Naval Research (ONR), Naval Health Research Center (NHRC), Chief of Naval Air Training (CNATRA), United States Army Aviation Center of Excellence (USAACE), and Air Force Air Education and Training Command (AETC). 

REFERENCES: 

1: Afergan, D., Peck, E. M., Solovey, E. T., Jenkins, A., Hincks, S. W., Brown, E. T., ... & Jacob, R. J. (2014, April). Dynamic difficulty using brain metrics of workload. In Proceedings of the 32nd annual ACM conference on Human factors in computing systems (pp. 3797-3806). ACM.

2:  Cui, X., Bryant, D. M., & Reiss, A. L. (2012). NIRS-based hyperscanning reveals increased interpersonal coherence in superior frontal cortex during cooperation. Neuroimage, 59(3), 2430-2437.

3:  Doyon, J., Ungerleider, L. G., Squire, L., & Schacter, D. (2002). Functional anatomy of motor skill learning. Neuropsychology of memory, 3, 225-238.

4:  Ferrari, M., & Quaresima, V. (2012). A brief review on the history of human functional near-infrared spectroscopy (fNIRS) development and fields of application. Neuroimage, 63(2), 921-935.

5:  Raley, C., Stripling, R., Kruse, A., Schmorrow, D., and Patrey, J. (2004). Augmented cognition overview: improving information intake under stress. Proc. Hum. Factors Ergon. Soc. Annu. Meet. 48, 1150–1154.

KEYWORDS: Functional Near Infrared Spectrometry, FNIRS, Neurofeedback, Hyperscanning, Aviation, Physiology, Psychology, Neuroscience 

TECHNOLOGY AREA(S): Materials, Sensors, Electronics, Battlespace 

OBJECTIVE: Develop a technology similar to a scanning probe microscope capable of simultaneously measuring the variation of surface potential/Local Density of States and topography to image and identify defects with near atomic spatial resolution in modern electronic devices. 

DESCRIPTION: The demand for higher computing speeds for electronic systems has resulted in the shrinkage of devices features and a higher density of transistors in integrated circuits (ICs). This shrinkage of device geometries has induced a variety of challenges for the metrology of electronic devices including the measurement of narrow trenches and holes for failure analysis and in-line process control. There are multiple techniques for characterization of electronic devices such as critical dimension scanning electron microscopy (CDSEM), transmission electron microscopy (TEM), optical scatterometry (OCD), atomic force microscopy (AFM) and x-ray microscopy (XRM). However, there are limitations associated with each of these techniques with respect to preservation of device functionality, low spatial resolution, and/or small field of view. For instance, both CDSEM and TEM induce charging of non-conducting samples, and they provide information only about specific sections of samples and require destructive sample preparation. AFM techniques requires less sample preparation; however, it often offers a maximum scanning area of 150 by 150 micrometer square in comparison to SEM with millimeter square scan sizes. The sample preparation for XRM technique is also less destructive; however, this method provides a maximum spatial resolution of 30 to 40 nm and in most cases is very expensive as it requires light synchrotrons for generation of x-rays. Alternatively, kelvin probe force microscopy (KPFM), which is an AFM based apparatus provides nanometer-scale imaging of the sample surface potential to characterize the electronic properties of semiconductor devices to determine various characteristics of samples ranging from doping and composition to defects in dielectrics. However, KPFM does not offer near-atomic scale imaging, which can be used to acquire information on processes that induced defects and their impact on the functionality of electrical devices. Hence, the performer is expected to evaluate, develop and/or integrate techniques to simultaneously measure surface potential and image surface topography with high spatial resolution (less than 10 Å) to identify defects in transistors. 

PHASE I: Perform a feasibility study on various methods to measure surface potential while imaging to identify defects for characterization of electrical devices. The end result of this performance is a report that provides all the rational justification for the proposed technique. The feasibility report should address the following constraints: ‒ The proposed method shall provide near atomic (less than 10 Å) topographic imaging and measurement of surface potential. ‒ The proposed method shall require non-destructive sample preparation to preserve device performance. ‒ The proposed method shall not alter device functionality. ‒ The proposed method shall consider the varying materials present in semiconductors (including but not limited to silicon, silicon dioxide, silicon nitride, copper, aluminum, sapphire, tungsten, tantalum, etc.). ‒ The proposed method shall be capable of defect characterization in semiconductor transistors including but not limited to gate oxides of Fin Field-effect transistors (FinFETs).  

PHASE II: Phase II will result in building, testing and delivering a fully functional prototype or technology of the method developed in phase I. Deliver the testing data and the samples for which the experiments were performed. Deliver all the supporting documents, including CAD drawings, analysis, developed hardware and software components, and process flows. At minimum four samples need to be delivered. Two samples will represent transistors with the smallest technology node that the prototype can characterize. The other two samples will represent other materials systems to support the constraints noted in Phase I. The performer is expected to show repeatability between similar samples having the same materials and features. 

PHASE III: Phase III will result in the expansion of the prototype system in Phase II into a tested pre-production system. The system encompasses a technique capable of simultaneous surface potential measurement and topographic imaging for precise defect identification. This system has applications for evaluating failures of integrated circuits (ICs) both in commercial and government sectors. 

REFERENCES: 

1: M. K. Lee, et al., Applications of AFM in Semiconductor R&D and Manufacturing at 45 nm Technology Node and Beyond, Proc. of SPIE 7272 (2009) 72722R-1 to 72722R-12.

2:  W. Melitz, et al., Kelvin probe Force Microscopy and its Application, Surface Science Reports 66 (2011) 1–27.

3:  F.M. Battiston, et al., Combined Scanning Tunneling and Forcemicroscope with Fuzzy Controlled Feedback, Appl. Phys. A 66 (1998) S49–S53.

4:  J. Deng, et al., Nanoscale X-ray Imaging of Circuit Features without Wafer Etching, Phys Rev B. 95 (2017).

KEYWORDS: SPM, Surface Potential, Characterization, Failure Analysis, Semiconductor Devices, ICs 

TECHNOLOGY AREA(S): Sensors, Weapons 

OBJECTIVE: The objectives of this effort are to: 1) Develop an optically based temperature diagnostic (for characterizing temperature fields ranging 300-3000 K) to interrogate detonation environments and 2) provide a hardened/scalable capability for interrogating a detonation environment. 

DESCRIPTION: Weapon-target interaction during a counter-WMD operation and ensuing neutralization within the target environment need to be characterized and understood to evaluate the full effect of counter-WMD operations on targets. Characterization capabilities are needed to assess the confidence in immediate lethality of a weapon formulation against an agent and potential longer term viability of the threat. The immediate payoff of these research efforts is expected to be the development of a diagnostic to quantify localized temporal evolution of temperature, inside a blast/fireball, which in turn will vastly improve blast and weapon modeling. This diagnostic development is critical for predicting weapon effectiveness against WMD targets. Therefore, the work from this topic will help generate statistically richer data sets for future decision making in support of defense applications. Over the last decade or more, the combustion community has made significant advances in laser based diagnostic capabilities [1-4]. A number of techniques have demonstrated great promise in this field (e.g. Coherent Anti-Stokes Raman Spectroscopy (CARS), Planar Laser Induced Fluorescence (PLIF), absorption spectroscopy (single mode and supercontinuum), etc.). The detonation science community has been slow to adopt some of these innovative capabilities either due to cost, personnel expertise, or technological/logistical risk. Some of these reasons may no longer be sufficient nor applicable; however, some challenges still remain. Some universities and other government laboratories have made progress in terms of characterizing temperature and other metrics of interest [5]. The topic here is focused solely on temperature characterization in a post-detonation field that includes CHNO and metallized charges. If pulsed laser capabilities are chosen in response to this topic, then high repetition rate lasers (>1 kHz) are desired. Capabilities that lend well to characterizing a temperature field (e.g. 2D field or 3D volume) are also of interest. Point/line integrated capabilities (excluding H2O absorption) that may complement existing non-optical capabilities to enhance statistical collection would also be relevant. Some challenges in characterizing detonation environments persist. For consideration within this topic, offerors need to consider the high optical thickness of the associated fireball (approaching 5-6 logs in some regimes). Other environmental challenges include being in particle laden flows and the harsh blast pressure and temperature environments that may damage equipment in or near the fireball. Consider that other enabling technologies (e.g fiber lasers, QCLs, LWIR fiber) may make a concept transitionable from a university lab environment to a fieldable capability. The scalability (e.g costs, number of sensors, etc.) of a given concept along with generating sufficient statistics (e.g. time domain, spatial domain, etc.) for detonation environments will be important considerations. 

PHASE I: ) Develop an optically based and cost-scalable sensing capability for characterizing a large range of temperatures 500K-3000K for small scale detonation (or simulated detonation). 2) Demonstrate concept in a (simulated) blast environment. 

PHASE II: 1) Produce a breadboard capability that is hardenable/scalable for field testing. 2) Ship for preliminary performance evaluation to a Navy lab and/or other test facility. 3) Demonstrate performance over temperature range in a mid-scale detonation test. Stand-alone capabilities or those that are orthogonal to exisiting (non-optical) capabilities which might enhance statistical collection are of interest. Hardening measures and/or beam transport will need to be considered. 

PHASE III: Team up with a DoD Laboratory or commercial partner to develop a commercial instrument for military applications of interest to DTRA and the DoD, or for applications of interest to the petroleum and chemical industries. 

REFERENCES: 

1: Chloe E. Dedic, Terrence R. Meyer, and James B. Michael, "Single-shot ultrafast coherent anti-Stokes Raman scattering of vibrational/rotational nonequilibrium," Optica 4, 563-570 (2017).​​

2:  T. Werblinski, S.R. Engel, R. Engelbrecht, L. Zigan, S. Will, "Temperature and mult-species measurements by supercontinuum absorption spectroscopy for IC engine applications," Optics Express 21, (2013). ​​

3:  S. P. Kearney and D. R. Guildenbecher, "Temperature and oxygen measurements in a metallized propellant flame by hybrid fs/ps rotational coherent anti-Stokes Raman scattering," in Imaging and Applied Optics 2016, OSA technical Digest (online) (Optical Society of America, 2016), paper LW5G.3.​​

4:  Anna-Lena Sahlberg, Dina Hot, Johannes Kiefer, Marcus Aldén, Li Zhongshan, "Mid-infrared laser-induced thermal grating spectroscopy in flames", Proceedings of the Combustion Institute, 36, 4515-4523 (2017).​​

5:  DTRA Basic Research Broad Agency Announcement HDTRA1-11-21-BRCWMD-BAA, Period F-Topic 7: Dynamic Characterization of Post-Detonation Fireballs Involving Agent Defeat Additives and Agent Simulants​​

KEYWORDS: Temperature, Lasers, Spectroscopy, Weapons 

TECHNOLOGY AREA(S): Chem Bio_defense 

OBJECTIVE: Enable military operators to identify novel and partially occluded laboratory equipment 

DESCRIPTION: Military operators need to identify laboratory equipment they encounter in facilities (DTRA-17-BAA-RIF-0001)1. Currently, machine learning algorithms are being used to aid in object identification. However these algorithms are very dependent on the labelled training set used to train the models and can fail when real world conditions differ from the training set used (e.g. pristine pictures of laboratory equipment from a catalog vs pictures where objects are partially occluded). Additionally, traditional machine learning algorithm based approaches can fail if they encounter novel objects that might have the exact function but not appearance of an object used in the training set (e.g. two different brands of thermal cyclers). There is a need for improved methods to detect and classify objects which can overcome the challenges mentioned above. Recent advances in computer science may aid in overcoming the above challenges by taking into account the context in which the object appears in conjunction with other objects (e.g. co-occurrence, relative location, etc.)2,3 as well as background knowledge using approaches such as knowledge graphs4. For example a beaker with a stir bar and liquid inside it that is on top of an unidentified plate may have a higher probability of being a magnetic stir plate due to the relative location of the different objects. While developed methodologies will be tailored for use by DTRA for improved identification of laboratory equipment, it is expected they will have a broader potential customer base for any technology which requires object identification. Multidisciplinary teams composed of experts in areas such as machine learning, knowledge graphs, statistical based approaches, and the life sciences are preferred. Laboratory equipment shall be limited to equipment used in the life sciences area. Proposals should identify and explain the content of the data sources they propose to use. Teams should be self-sufficient and should not rely on DTRA to identify relevant relationships or provide data. 

PHASE I: The phase I deliverable is a report and preliminary proof of concept demonstration detailing the methods used for 1) improved identification of occluded life science laboratory equipment. The performer shall identify, collect, label, and identify relationships for 100 life sciences laboratory equipment. The performer shall develop metrics to measure performance. The report shall detail the (1) advantages and disadvantages/limitations of the proposed methods (2) benchmark data, and (3) preliminary proof of concept demonstration. 

PHASE II: The phase II deliverable is a final report and final proof of concept demonstration detailing the methods used for 1) improved identification of occluded life science laboratory equipment and 2) identification of the function of previously unseen (i.e.no labelled training data available) life sciences laboratory equipment. The performer shall identify, collect, label, and identify relationships for 1000 life sciences laboratory equipment. The performer shall continue to measure performance. The final report shall detail the (1) advantages and disadvantages/limitations of the proposed methods (2) benchmark data, and (3) demonstration. 

PHASE III: Finalize and commercialize software for use by customers (e.g. DTRA, industry). Although additional funding may be provided through DoD sources, the awardee should look to other public or private sector funding sources for assistance with transition and commercialization. 

REFERENCES: 

1: ​ https://www.fbo.gov/utils/view?id=51f3d824eac86a5d861dfce4415eb8b4#_Toc440615665

2:  ​Hong, Jongkwang, et al. "Discovering overlooked objects: Context-based boosting of object detection in indoor scenes." Pattern Recognition Letters 86 (2017): 56-61

3:  ​Guan, Linting, Yan Wu, and Junqiao Zhao. "SCAN: Semantic Context Aware Network for Accurate Small Object Detection." International Journal of Computational Intelligence Systems 11.1 (2018): 936-950

4:  ​Fang, Yuan, et al. "Object detection meets knowledge graphs." (2017)

KEYWORDS: Context Dependent Learning, Knowledge Graphs, Bayesian, Lab Equipment, Object Identification, Computer Vision 

TECHNOLOGY AREA(S): Materials, Sensors, Nuclear 

OBJECTIVE: The topic seeks to advance the current state of the art in materials research for the detection of SNMs and WMDs. The emphasis is on the efficient detection of neutrons as well as gamma-rays, with superior neutron/gamma discrimination and better gamma-ray energy resolution than that of NaI:Tl using fast organic materials that are deemed low cost and rugged. 

DESCRIPTION: Innovative approaches for low-cost organic scintillation materials that enable dual-mode, neutron/gamma radiation detection are sought. The proposed materials or systems may include new compositions and designs, or improve upon the existing ones through recently developed methods of materials and systems engineering. The key performance requirements are to develop dual-mode, e.g. sensitive to both neutrons and gammas, scintillators that can retain the excellent neutron detection and PSD characteristics of stilbene, while adding increased gamma-ray sensitivity and energy resolving capability for isotope identification, as well as providing faster decay time over stilbene for high count rate applications and TOF studies. The use of these materials will allow development of integrated detection systems capable of high count rates to utilize TOF techniques for neutron imaging and neutron energy information, dual gamma-ray and fast neutron detection with high sensitivity and PSD, better energy resolution and isotope identification than that of NaI:Tl. Commercial inorganic scintillators provide many of these characteristics but are often expensive and not available in large sizes, while organic single crystals such as stilbene provide efficient fast neutron detection and good PSD but lack gamma-ray spectroscopy and are still relatively expensive. Hence, in addition to the key performance requirements mentioned above, the proposed materials or systems must include a cost-benefit analysis relative to the commercially available options. It is anticipated that the proposed materials can be scaled to very large sizes in a cost effective manner unlike the current, state-of-the-art inorganic scintillator technologies. 

PHASE I: Phase I must demonstrate the feasibility of the selected materials and/or systems to provide efficient gamma-ray and neutron detection in combination with neutron/gamma PSD with a Figure-Of-Merit (FOM) equal to or better than that of stilbene, while having improved gamma-ray sensitivity and spectroscopic capabilities. Detectors or systems that can provide high count rates and TOF capabilities are preferred. At the end of Phase I, demonstrate pathways for scaling up the materials to 1” (diameter) x 1” (length), and meet the following performance goals: • Light yield greater than 10,000 photon/MeV; • Energy resolution better than that of NaI:Tl, or< 7% (FWHM) at 662 keV; • Faster scintillation decay time than that of stilbene (<2 ns); • Neutron/Gamma PSD equal to or better than that of stilbene (FOM> 3); • Unit cost of the materials/systems lower than that of stilbene. 

PHASE II: Further develop the chosen production methodology from Phase I and produce larger organic scintillators, e.g. > 3” (diameter) x 3” (length) with targeted performance goals. By the end of Phase II development, mature materials production process must be established, as well as pathways towards achieving low cost materials production. At the end of phase II, the goal is to fully commercialize 2” (diameter) x 2” (length) chosen organic scintillators, with the objective to commercialize even larger size crystals. Prototype instruments that integrate the chosen organic materials with optical readout, e.g. PMT or SiPM, shall be developed and demonstrated in Phase II and delivered to DTRA for further evaluation. 

PHASE III: Team up with national laboratories or commercial partners to develop commercial quality prototype instrument utilize the developed fast organic scintillator to accomplish the goals of neutron and gamma-ray detection in combination with efficient neutron/gamma PSD and gamma-ray spectroscopy. The commercial prototype instrument should provide unprecedented capabilities to DTRA for Warfighter’s missions, domestic security and commercial applications to support first responders and regulatory inspections, border and port security, power plant maintenance, and environmental clean-up, etc. 

REFERENCES: 

1: ​ANSI N42.34, American National Standard Performance Criteria for Hand-Held Instruments for the Detection and Identification of Radionuclides.

2:  ​G. Knoll, Radiation Detection and Measurement, Wiley, 2010.

3:  ​Market Survey Report

4:  https://www.dhs.gov/sites/default/files/publications/ND-PRD-MSR_0215-508_0.pdf.

KEYWORDS: Low-cost Fabrication Methods, Organic Scintillation Materials, Gamma-ray Detection, Neutron Detection, Neutron/gamma Pulse Shape Discrimination, Gamma-ray Spectroscopy 

TECHNOLOGY AREA(S): Air Platform, Ground Sea, Electronics 

OBJECTIVE: Design and develop a model and simulation (M&S) tool to establish the overall aircraft system-of-systems (SoS) thermal management to determine the least efficient sub-system so that improvements can be made to increase the overall aircraft energy efficiency. 

DESCRIPTION: The aircraft is a SoS that presently is not well defined with respect to overall thermal management, with only the individual systems defined including their size and weight. The Navy seeks a tool that can accurately model the overall thermal management of the aircraft SoS, including all individual sub-systems (i.e., fuel, engine, Aircraft Mounted Accessory Drive (AMAD), electrical, avionics, sub-systems, fuel/air energy processes), to determine where improvements can be made to overall efficiency. This model would be used to assess and quantify failure modes on the aircraft when changes/improvements are made to individual sub-systems for present and future aircraft upgrades. Avionics upgrades increase generator electrical load, which increases the heat to the generator cooling oil. The cooling oil increases heat transfers to an oil/fuel heat exchanger to the fuel. Additionally, the radar upgrades would increase heat that goes through a Polyalphaolefin Liquid to the fuel heat exchanger. Any engine upgrades may also increase the engine heat that transfers through the engine oil to the fuel. The increased heat to the fuel can coke the engine. The tool should be developed using the known thermal aircraft predicted loads that are defined in the thermal load analysis. The model would use predicted heat loads (kilo-watts) and calculate the resultant temperature data. The calculated temperatures will be compared to aircraft temperature data archived by Boeing to test the model’s validity. Fighter aircraft temperature data and thermal load analysis will be provided by the Government. As upgrades occur, the software would be used to predict thermal increases. The tool should have the ability to import data from Microsoft Excel. 

PHASE I: Define and develop an approach for a modeling and simulation tool able to analyze existing fighter aircraft heat loads using data to be provided by the Government. Ensure that the model approach is capable of adding future heat loads that result from an aircraft upgrade. The Phase I effort will include prototype plans to be developed under Phase II. 

PHASE II: Develop and demonstrate prototype software modeling and simulation tool for an aircraft system. Validate the software using Government-furnished thermal and temperature data. 

PHASE III: Develop and demonstrate a platform-specific thermal management system modeling tool using temperature data. Transition the tool to appropriate program offices. Commercial aircraft and automotive manufacturers can benefit from using the model to determine the thermal impact on cooling systems. 

REFERENCES: 

1. Ahlers, Mark. “Aircraft Thermal Management: Systems Architectures.” . SAE International, April 30, 2016; ISBN-10: 076808296X; ISBN-13: 978-0768082968. https://www.sae.org/publications/books/content/pt-177/; 2. Sundén, Bengt and Fu, Juan. “Heat Transfer in Aerospace Applications.” Academic Press, 2017; ISBN 978-0-12-809760-1. https://www.elsevier.com/books/heat-transfer-in-aerospace-applications/sunden/978-0-12-809760-1

KEYWORDS: Thermal; Integration; Fuel; Electrical; Oil; Analysis 

TECHNOLOGY AREA(S): Air Platform, Ground Sea, Materials 

OBJECTIVE: Develop a comprehensive toolset to predict the fatigue life of flight-critical metallic components fabricated by additive manufacturing. 

DESCRIPTION: Additive manufacturing (AM) is considered a revolutionary technology to fabricate lightweight, flight- and marine-critical metallic components. The ability to produce complex and tailored structure designs opens the door for improved efficiency in existing products and can function as a key enabler to new uses like hypersonic applications. Many merits, such as high efficiency, flexibility, and cost saving, give AM the potential to become a widely utilized fabrication process for industrial applications. Despite the high potential of this manufacturing technology, it has been found that the fatigue life of as-deposited AM components is often low compared to wrought components produced by conventional technology. For critical components, like those in airframe applications, developing a better understanding of fatigue performance is essential for further adoption of this technology [Ref 1]. AM is far more complex than traditional fabrication processes. The starting material is typically a high-quality powder with specific characteristics such as size, morphology, and chemical composition. The AM process is comprised of numerous cycles of material addition and rapid heating and cooling / melting and solidifying. As a result, the fatigue performance in AM parts has been attributed to a complex combination of material and process-induced imperfections. For example, fatigue crack growth mechanisms have been correlated with microstructure, such as a/a’ phases and colonies, in AM-fabricated Ti-6Al-4V [Ref 2]. Fatigue performance has also been found to be strongly related to porosity and defects that could be formed due to localized incomplete melting, often influenced by process parameters [Ref 3]. As with traditional machine design rules, the fatigue lives of an AM part are dominated by surface roughness effects. The effect of residual stress on fatigue performance has also been demonstrated by removing a compressive residual stressed surface layer to reduce fatigue performance [Ref 4]. Due to the complexity of fatigue behavior of an AM part, a comprehensive toolset, based on an Integrated Computational Materials Engineering (ICME) framework [Ref 5], is needed to predict fatigue strength and fatigue life in AM metallic components. This toolset should address the fatigue contributing factors at the part level, such as residual stress during the AM process, the microstructure of the fabricated metallic component, porosity level and distribution in the AM part, and surface roughness. This toolset should be able to assess fatigue environments typically experienced by Navy aircraft like flight spectra [Ref 6] and shocks and vibration [Ref 7]. Similar to the integrative approach in foundry processes (castings) [Ref 8], the AM fatigue predictive methodology may integrate a combination of AM process simulations to predict AM anomalies, crack growth modeling to predict the effect of the AM anomalies on fatigue life and residual strength, and modeling of nondestructive evaluation (NDE) processes to determine the inspectability of both initial anomalies and potential cracks that may grow while the component is in service. Artificial intelligence strategies like machine learning and neural networks may be integrated into the toolset. This toolset should be compatible with existing analysis software toolsets (e.g., FE-SAFE [Ref 9], nCode [Ref 10], AFGROW [Ref 11], NASGRO [Ref 12]) and exhibit equal or better performance and accuracy. Component size limitations are largely driven by the build volume of the AM machine being used. As the technology continues to evolve, so will the build volume. For purposes of this effort, components between 2”x2”x2” and 15”x15”x15” are acceptable, however the long-term goal is for larger capability. 

PHASE I: Demonstrate the feasibility of a predictive methodology for fatigue properties of metallic AM components (relating the material and processing induced imperfections noted above.) Show the feasibility by performing limited predictions of the fatigue performance of a single material (e.g., Ti-6Al-4V or 17-4PH) for a single AM machine. Validate the predicted fatigue behavior of the deposited material and characterize at a coupon level. Identify the issues involved in integrating the fatigue predictive methodology. Include, in a Phase II plan, full-scale methodology development plans to be carried out under Phase II. 

PHASE II: Further develop the predictive toolset so that it can be applicable to an array of aircraft component geometries and materials, and useable across multiple machines (e.g., one powder bed machine and one powder blown machine.). Demonstrate the predictive tool on an article that is representative of basic geometries seen on aircraft components (e.g., overhangs, holes, fillets/radii, internal channels, lugs). Perform analysis of the predictive methodology to determine its ability to predict fatigue behavior of AM parts. Fully validate the predictive fatigue lives of the AM parts. 

PHASE III: Fully develop the predictive fatigue toolset and demonstrate it in a scenario representative of Navy implementation (i.e., using similar equipment, skillsets, and selected part(s) that would be available in a Navy application). Transition the prediction tool into a standalone and/or combined product for use in Navy and commercial additive manufacturing applications. Ensure that the software tool developed through this effort will enable designers and manufacturers to better identify and address features, characteristics, and potential anomalies that could negatively impact fatigue life prior to part production, which will help to improve the quality of additively manufactured parts as well as increase the efficiency of the AM process by reducing the number of builds that fail to meet performance requirements. As these aspects are valuable to all types of AM, this toolset will be directly applicable to a wide range of commercial applications (e.g., aerospace, marine, automotive, and oil and gas.) 

REFERENCES: 

1. Li, P., Warner, D., Fatemi, A., and Phan, N. "Critical assessment of the fatigue performance of additively manufactured Ti–6Al–4V and perspective for future research." International Journal of Fatigue, Volume 85, April 2016, pp. 130-143. https://doi.org/10.1016/j.ijfatigue.2015.12.003; 2. Zhai, Y., Galarraga, H., and Lados, D. A. "Microstructure, static properties, and fatigue crack growth mechanisms in Ti-6Al-4V fabricated by additive manufacturing: LENS and EBM." Engineering Failure Analysis, Volume 69, 2016, pp. 3-14. https://doi.org/10.1016/j.engfailanal.2016.05.036; 3. Hrabe, N., Gnäupel-Herold, T., and Quinn, T. "Fatigue properties of a titanium alloy (Ti–6Al–4V) fabricated via electron beam melting (EBM): Effects of internal defects and residual stress." International Journal of Fatigue, Volume 94, 2017, pp. 202-210. https://doi.org/10.1016/j.ijfatigue.2016.04.022; 4. Golden, P.J., John, R., and Porter, W.J. "Investigation of variability in fatigue crack nucleation and propagation in alpha+beta Ti–6Al–4V." Procedia Engineering, Volume 2, 2010, pp. 1839-1847. https://doi.org/10.1016/j.proeng.2010.03.198; 5. "Integrated Computational Materials Engineering: A Transformational Discipline for Improved Competitiveness and National Security." National Research Council, 2008. https://doi.org/10.17226/12199; 6. Heuler, P. and Klatschke, H. “Generation and use of standardized load spectra and load-time histories.” Int. J Fatigue, 2005, Volume 27, pp. 947-990. https://doi.org/10.1016/j.ijfatigue.2004.09.012; 7. “Department of Defense Test Method Standard, Environmental Engineering Considerations and Laboratory Tests,” Revision G.” Military Standard (MIL-STD-810G), 31 October 2008. http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL-STD-810G_12306/; 8. Bordas, S. P., Conley, J. G., Moran, B., Gray, J., and Nichols, E. "A simulation-based design paradigm for complex cast components." Engineering with Computers, March 2007, Volume 23, Issue 1,, pp. 25-37. https://doi.org/10.1007/s00366-006-0030-1; 9. "FE-SAFE - Durability Analysis Software for Finite Element Models." Dassault Systemes, 2018. https://www.3ds.com/products-services/simulia/products/fe-safe/fe-safe/; 10. “nCode DesignLife.” HBM Prenscia Inc., 2018. https://www.ncode.com/products/designlife-cae-fatigue-analysis; 11. “AFGROW (Air Force Growth) Fracture Mechanics and Fatigue Crack Growth Analysis Software.” LexTech, Inc., 2015. https://www.afgrow.net/; 12. “NASGRO Fracture Mechanics & Fatigue Crack Growth Software.” Southwest Research Institute, 2018. https://www.swri.org/consortia/nasgro; 13. Fieres J., Schumann, P., and Reinhart, C. “Predicting failure in additively manufactured parts using X-ray computed tomography and simulation.” Procedia Engineering, Volume 213, 2018, pp. 69-78. https://doi.org/10.1016/j.proeng.2018.02.008; 14. Yadollahia A., Shamsaeia N., Thompsona S.M., Elwanyb A., Biana L., Mahmoudib M., “Fatigue behavior of selective laser melted 17-4 PH stainless steel.” 26th International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, At Austin, TX, pp. 721. https://doi.org/10.13140/RG.2.1.3996.2323

KEYWORDS: Metal Additive Manufacturing; Fatigue Property Prediction; Process Modeling; Crack Growth; Non-destructive Evaluation; ICME 

TECHNOLOGY AREA(S): Air Platform 

OBJECTIVE: Develop computationally efficient, Computational Fluid Dynamics (CFD), flow modeling toolsets suitable for modeling 3D time-resolved conjugate heat transfer (CHT) for use in predicting thermal behavior of aircraft parts including gas turbine (GT) engines. 

DESCRIPTION: The Navy currently lacks a detailed 3D heat rejection system design or analysis capability. Most aircraft platforms have a substantial need to develop a better understanding of heat rejection / heat transfer in Navy systems. The science of modeling heat transfer in the presence of high-speed turbulent flow is crucial to Navy systems. Current CFD practice is to heavily simplify the airflow modeling, which removes important physics phenomena. Wall Modeled Large Eddy Simulation (WMLES)-based CFD toolset do an outstanding job of flow modeling turbulent flow, particularly in separated and poorly behaved flow cases. With improvements to the heat transfer modeling, particularly in the boundary layer, the state of the art will be improved, allowing improved design efforts, benefitting warfighter customers. One of the most important factors determining performance, reliability and safety in aircraft systems is the thermal state of the many subsystems. Incorrectly modeled or estimated thermal effects can lead to premature degradation of components, which increases both maintenance costs and safety risk. This topic is aimed at providing to the NAVAIR Internal Flow Modeling Team (NIF-T) a toolset that will allow them to accurately solve conjugate heat transfer (CHT) problems for the benefit of the Navy fleet and program office aircraft propulsion and power customers. Fully detailed 3D CHT modeling has long been difficult to accomplish. Its complexities are commonly side-stepped in favor of simpler (often over-simplified), far less accurate, approaches. This is especially true in current CFD state of the art toolsets, where heat transfer is often modeled using simplified flow models, using over-simplified (uniform) temperature or uniform heat flux boundary conditions. Currently available solvers, such as ANSYS Icepak [Ref 1], used commercially for analysis of CHT problems, typically focus on modeling the cooling of consumer electronics. This has been shown to be an effective tool for convection or fan forced cooling in electronics applications. However, it lacks significantly in modeling the physics of high speed / transonic / supersonic flow such as in military GT engines. The flow field in electronics is typically modeled acceptably using either direct numerical simulation (DNS) or Reynolds-Averaged Navier-Stokes (RANS) simulations. RANS solvers are often used by industry in GT engine analyses as well due to their less computationally expensive nature. When used with care, RANS can give reasonable accuracy in well-behaved flow cases. The RANS formulation relies on turbulence models to model boundary layer stress, but do not work as well with separated, poorly-behaved turbulent flows. Large Eddy Simulation (LES) is a well-known approach to flow modeling that has been implemented in many commercial CFD toolsets. It is very good at accurately modeling time-varying turbulent flow of features at grid scale and above, while moderating the computational cost as compared to DNS. LES, while providing increased accuracy over RANS, comes at the expense of increased (5-10X) computational resource requirements (when modeling high speed flow around solid objects where an accurate representation of the flow behavior in the boundary layer is desired) as compared to RANS methods. To mitigate the non-linear growth of computational requirements with increasing flow complexity, the state of the art in LES has recently advanced with the introduction of wall modeling of boundary layers [Ref 2]. This allows for substantial grid size reduction which greatly reduces the computational requirements for accurate LES solutions. However, the various optional boundary layer turbulence / shear assumptions of the many different Wall Modeled Large Eddy Simulation (WMLES) approaches have, in most cases, not been carefully studied in order to develop accurate heat transfer predictions through this simplified boundary layer region. Many flow analysis organizations, have come to rely on the outstanding unsteady flow predictions of WMLES toolsets. This STTR topic seeks to further develop and improve the accuracy of the CHT predictions of WMLES toolsets, both with and without transpiration. It seeks to improve wall modeling assumptions such that CHT analysis results accurately predict the physics of heat transfer in turbulent boundary layers. We are seeking to develop toolsets that accurately predict CHT in selected sample cases with known results that are (threshold) at least as accurate as RANS model CHT results, with the objective being that the use of wall modeling produces CHT results that are equally as accurate as fully resolved (not wall modeled) LES analyses. The proposed toolset must be able to accurately model the heat transfer between the fluid and the bounding structures within the respective domains of each. These toolsets must work in a computationally efficient manner, with the objective that accurate CHT results take no more computing resources than current WMLES analyses. The Threshold would be that any changes to the Wall Modeling features would result in WMLES models with accurate CHT calculations that use less computing resources that fully resolved LES models while the CHT features are active. Any proposed toolset would be evaluated primarily on physical accuracy for both flow properties and CHT in wall regions, and secondarily on computational efficiency. Physical accuracy would need to be demonstrated against experimental results of the physics being modeled, and other well accepted WMLES tool results. Experimental comparisons are to be chosen by the proposing organization to demonstrate accuracy of the toolset when given arbitrary problems as well as established problems, while following simple modeling guidelines. Computational efficiency of the toolset would be demonstrated with representative and real-world flow problems being simulated on the DoD high-performance computers [Ref 7] (or functional equivalent) with threshold and objective measures as described above. Note that the task / cost of developing new wall modeling features in an LES toolset that lacks wall modeling is outside the scope of this topic. Preference will be given in the Phase II selection process for proposing entities working with an already implemented LES toolset with wall modeling for accurate boundary layer flow prediction. However, an approach that selects an LES toolset currently without wall modeling would be allowed as long as the proposal commits to delivering, at the end of Phase II, a fully functional WMLES toolset that meets the objectives stated herein. Two known open source LES toolsets are High Fidelity Large Eddy Simulation (HiFiLES) [Ref 3] and OpenFOAM [Ref 4]. 

PHASE I: Demonstrate an in-depth knowledge of the physics and modeling issues involved in modeling turbulent air flow and making CHT predictions, with and without transpiration using both RANS and WMLES toolsets. Select one currently available WMLES toolset to be updated / demonstrated for this effort, and one RANS tool for use in flow and CHT results comparison for this effort. Define and describe a plan for confirming / improving / demonstrating the CHT features of the selected WMLES toolset, to be carried out in Phase II. Develop a detailed plan (to be carried out in Phase II) to conduct one or more proof-of-concept demonstrations of the predictive power and accuracy of the proposed resulting toolset that must include measures of its computational efficiency. Provide a risk analysis of the proposed Phase II effort, identifying key areas of technical risk, and provide a risk mitigation plan for each identified risk. (Note: Technical Risk is defined here as: “issues arising from, or aspects related to the contractor selected approach that could result in a less than satisfactory result, based on the measures of success in this solicitation”.) 

PHASE II: Carry out the contractor’s development and demonstration plan for improved CHT modeling with the selected WMLES toolset (as defined in Phase I above). Enhance and / or demonstrate accurate CHT modeling performance (as described above) of the selected WMLES toolset. Demonstrate scalability, universality and applicability of the solver, including its computational efficiency for use in real-world, GT propulsion relevant flows. Evaluate, document, and demonstrate the CHT predictive power of the toolset using a contractor-obtained test data set, selected by agreement with the NAVAIR TPOC. By the end of the Phase II effort, deliver and install a working prototype version of the resulting enhanced WMLES toolset on the DoD High Performance Computer Systems (DoD HPC). Obtain and provide to the Navy all needed licenses and enabling tools for input of model data and output of results. 

PHASE III: Perform testing and then any further development of the toolset to address any identified deficiencies to provide a commercially viable and well accepted CHT / WMLES toolset to be utilized by the developing organization as consultants and / or sold or licensed to other organizations. Deliver and install the final working version of the enhanced WMLES toolset on the DoD High Performance Computer Systems (DoD HPC), including all needed licenses and enabling tools for input of model data, and output of results. Train and assist up to 15 members of the NAVAIR NIF-T team in the use of the final WMLES toolset. The toolset developed here are expected to have far-reaching uses for all DoD branches and many private sector companies. GT design as well as aircraft design in general would benefit from robust 3D flow-based heat transfer analysis, especially with regard to component reliability, performance, and efficiency of propulsion and cooling systems. Gas turbine engines are currently in use for land-based electrical power generation, ship power plants, land vehicles, and most aircraft. Beyond GT engines, accurate heat transfer calculations in an accurate WMLES flow modeling tool would have benefits for use in the design of gasoline and diesel engines, heat exchangers of all types, the refrigeration industry, nuclear reactor original equipment manufacturers (OEM), and design of general purpose heating, ventilation and air conditioning (HVAC). However, the high speed flow inherent in GT engines would perhaps most benefit from the combination of WMLES with accurate CHT. Potential uses exist for any industry where accurate CHT analysis would enhance design features, such as the refrigeration industry, automotive and surface vehicle, nuclear, HVAC etc. 

REFERENCES: 

1. “ANSYS Icepack: Electronics Cooling Simulation.” ANSYS Inc., 2018. https://www.ansys.com/products/electronics/ansys-icepak; 2. Bose, Sanjeeb T., and Park, George Ilhwan. “Wall-Modeled Large-Eddy Simulation for Complex Turbulent Flows.” Annual Review of Fluid Mechanics, 2018, Volume 50:535-61. https://doi.org/10.1146/annurev-fluid-122316-045241; 3. "HiFiLES - High Fidelity Large Eddy Simulation." Aerospace Computing Laboratory (ACL), Department of Aeronautics and Astronautics, Stanford University, 2014. https://hifiles.stanford.edu; 4. "OpenFOAM." OpenCFD Ltd. (ESI Group), 2018. https://www.openfoam.com; 5. Duchaine, F., Maheu, N., Moureau, V., Balarac, G., and Moreau S. “Large eddy simulation and conjugate heat transfer around a low-mach turbine blade.” Journal of Turbomachinery, American Society of Mechanical Engineers, Paper No: TURBO-13-1092, 136(5), 051015. http://turbomachinery.asmedigitalcollection.asme.org/article.aspx?articleid=1761870; 6. Gourdain, N., et al. “Large eddy simulation of flows in industrial compressors: a path from 2015 to 2035.” Philosophical Transactions of the Royal Society, A 2017 372 20130223, 2014. https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2013.0323; 7. Department of Defense High Performance Computing Modernization Program, 2018, https://centers.hpc.mil

KEYWORDS: Conjugate Heat Transfer; Heat Exchangers; Transpiration Cooling; High-Temperature Turbines; Large Eddy Simulation, LES; Wall Modeled LES; Gas Turbine Engines; 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Develop an Additive Manufacturing (AM) process for depositing inorganic glasses with sufficient quality and precision for free form and gradient index optics. 

DESCRIPTION: Naval Air Operations have a broad array of weapon and surveillance systems that utilize high performance optics. Many of these applications require greater wavelength transmission range, hardness, and temperature stability compared to polymers. The potential for utilizing AM technology to print glass lenses will provide the Navy the ability to (1) deposit net shape or near net-shape free-form optics, (2) locally adjust the index of refraction and other optical properties such as dispersion, (3) create high precision low thermal expansion meteorological frames that can form the basis for refractive optics, and (4) repair existing optical systems. The benefits of AM are widely realized for structural systems; however, work on printing optical systems is still in its comparative nascency. The majority of the work has been primarily focused on polymers. Processes that have been demonstrated for printing optically transparent polymers include ink-jet printing [Ref 1] with/without in-situ ultraviolet (UV) curing [Ref 2] and multiphoton stereolithography (SLA) to directly polymerize resin [Refs 3-4]. These techniques have been used for rapid prototyping of non-imaging optics using Poly(Methyl Methacrylate) (PMMA) like plastics [Ref 4]. They have also been used to create curved display surfaces, sensors, display devices, and interactive devices [Refs 1-2], and to print 3D Gradient Index (GRIN) devices by locally adjusting the index of refraction during the layer-by-layer fabrication [Ref 3]. This work has progressed to the point that it is beginning to be commercialized and while it is currently suitable for non-imaging purposes the technology is approaching viability for ophthalmic applications. Despite the benefits of inorganic glasses, there has been limited work applying AM processes to glasses. The high viscosity of glass when molten makes powder bed processes challenging because the bubbles fail to coalesce and escape due to buoyancy [Ref 5]. This can be overcome by using nanopowders to print a green part, followed by a slow high temperature burn-out/densification process [Refs 6-7]. Alternatively, fully dense material can be smoothly melted and deposited [Refs 8-9]. Both approaches have challenges and require significant development before optical devices can be successfully created. Currently no commercial AM system can be used to fabricate imaging quality optical glass with sufficient dimensional accuracy and surface finish. A robust AM process to fabricate optical materials with good optical properties and surface quality is needed. This AM process should be able to deposit optical materials within the desired transmission band and provide a smooth optical surface quality so that minimum post-processing is needed. This process will allow engineering of new optical systems with volumetrically varying properties such as the index of refraction (i.e., GRIN lenses). Even with homogeneous glasses, AM has the potential to rapidly realize free form optics or to repair existing systems with no or minimal post (such as least amount of time for a final polish to achieve a desired surface flatness, such as lambda / 4) processing. This will dramatically enhance the logistics and maintenance of Navy aircraft and other systems. To demonstrate a robust AM process, proposers are asked to develop an achromatic lens with a transmission window from 0.65 micrometer to 1.3 micrometer. • Clear aperture must be 3 inches in diameter • Effective Focal Length (EFL) must be 10 cm • Resolution must be 100 lp/mm • Athermalized design must work from -54 to 90 degrees Celsius • No adhesive should be used to combine the doublets Diameter Tolerance +0.00/-0.10 mm Focal Length Tolerance ±1% Surface Quality 40-20 Scratch-Dig Spherical Surface Power lambda /2 Spherical Surface Irregularity (Peak to Valley) lambda / 4 Centration =3 arcmin Clear Aperture >90% of Diameter Damage Threshold Pulse 5 J/cm2 (810 nm, 10 ns pulse, 10 Hz, 0.155 mm) CW 1000 W/cm (1070 nm, Ø0.971 mm) In addition, provide the following analysis and measured data: • Analyze Ray fan plots and spot diagrams • Demonstrate that the optical path length is equal to sigma n delta s for the two discontinuity between the doublets • Show the flatness of the wavefronts coming from a point source at the focus • Show what does n (lambda) curve looks like • Determine if power density at any image location is proportional to strength of corresponding object point? • Determine the birefringence of the material delta n • Determine the diffraction blur diameter • Determine the aberrations for the lens uinge the spot diagram to show these effects • Analyze spherical aberration; coma; astigmatism; distortion; transverse chromatic aberration • Determine the wavefront errors for Seidel aberration • Determine the Modulation Transfer Function (MTF) for this lens • Show what the optical plot of the optical transmission looks like 

PHASE I: Develop and demonstrate the feasibility of an AM process capable of the required optical properties, full densification, and smooth surface finish as provided in the description. The AM process should be able to realize a prescribed aspherical geometry with minimal post processing. Demonstration should include a fabrication plan of a representative achromatic lens with the specification provided in the description. Develop prototype plans to be developed under Phase II. 

PHASE II: Fully develop the AM process, demonstrated in Phase I, that can be applicable to an array of naval optical component geometries. Include, in the prototype demonstration, the effectiveness of fabricating fully densified optical components with precision control of the part geometry, and smooth surface quality. Fully characterize the resulting geometry, and mechanical and microstructural properties achieved through the process to validate the effectiveness of the AM process. 

PHASE III: Perform many experimental trials to define this additive manufacturing process since the development of an AM process for optical components is not a mature technology. Use simulation as a guide to help steer the direction of the experimentation; and to ensure the final product will meet the requirements of this topic as outlined in the specifications. Evaluate, by conventional metrology, the innovative achromatic doublet to ensure the AM process is on par with an achromatic produced by common practice. Transfer this process to platforms that have optical components. Perform testing and make improvements to the AM Process based upon the results. Begin producing optical components for testing and use in military systems. Laser manufacturers, camera manufacturers, and imaging technology manufacturers will benefit from this technology because they can now specify custom size optical components with unique transmission profiles that are not currently available with conventional optical processing. 

REFERENCES: 

1. Willis, K., Brockmeyer, E., Hudson, S., and Poupyrev, I. “Printed Optics: 3D Printing of Embedded Optical Elements for Interactive Devices.” 25th Annual ACM Symposium on User Interface Software and Technology, Cambridge, MA, Oct. 7-10, 2012, pp. 589–598. https://dl.acm.org/citation.cfm?doid=2380116.2380190; 2. Brockmeyer, E., Poupyrev, I., and Hudson, S. “PAPILLON: Designing Curved Display Surfaces With Printed Optics.” 26th Annual ACM Symposium on User Interface Software and Technology, St. Andrews, Scotland, UK, Oct. 8–11, 2013, pp. 457–462. https://dl.acm.org/citation.cfm?id=2502027; 3. Urness, Adam C., Anderson, Ken, Ye, ChungfangWilson, William L., and McLeod, Robert R. "Arbitrary GRIN component fabrication in optically driven diffusive photopolymers." Opt. Express 23, 2015, pp. 264-273. https://doi.org/10.1364/OE.23.000264; 4. Wang, B., Zhang, Q., Liu, Z., and Gu, M. "Two-photon direct laser writing of ultra-compact micro-lens system for fiber-optical magnetic microscopy probe." 2017 European Conference on Lasers and Electro-Optics and European Quantum Electronics Conference, Optical Society of America, 2017.https://www.osapublishing.org/abstract.cfm?URI=CLEO_Europe-2017-CM_P_20; 5. Khmyrov, R., Grigoriev, S., Okunkova, A., and Gusarov, A. “On the Possibility of Selective Laser Melting of Quartz Glass.” Phys. Procedia, 2014, Volume 56, pp. 345–356. https://www.sciencedirect.com/science/article/pii/S1875389214002624; 6. Kotz, F., Arnold, K., Bauer, W., Schild, D., Keller, N., Sachsenheimer, K., Nargang, T.M., Richter, C. Helmer, D., and Rapp, B.E. “Three-dimensional printing of transparent fused silica glass.” Nature, 544, pp. 337-340 (20 April 2017). https://www.nature.com/articles/nature22061; 7. Nguyen, D.T., Meyers, C., Yee, T.D., Dudukovic, N.A., Destino, J.F., Zhu, C., Duoss, E.B., Baumann, T.F., Suratwala, T., Smay, J.E., and Dylla-Spears, R. “3D-Printed Transparent Glass.” Adv. Mater., 1701181, pp. 1-5, 28 April 2017.; 8. Luo, Junjie. "Additive manufacturing of glass using a filament fed process." Doctoral Dissertation, 2017. http://scholarsmine.mst.edu/doctoral_dissertations/2565/?utm_source=scholarsmine.mst.edu%2Fdoctoral_dissertations%2F2565&utm_medium=PDF&utm_campaign=PDFCoverPages; 9. Klein, J., Stern, M., Franchin, G., Kayser, M., Inamura, C., Dave, S., Weaver, J. C., Houk, P., Colombo, P., Yang, M., and Oxman, N. “Additive Manufacturing of Optically Transparent Glass.” 3D Print. Addit. Manuf., 2(3), 2015, pp. 92-105. https://doi.org/10.1089/3dp.2015.0021; 10. Bogue, Robert. "Fifty years of the laser: its role in material processing." Assembly Automation, Volume 30, Number 4, 2010, pp. 317–322. https://www.emeraldinsight.com/doi/pdfplus/10.1108/01445151011075771; 11. Heinricha, Andreas, Ranka, Manuel, Maillarda, Philippe, Suckowa, Anne, Bauckhagea, Yannick, Rößlera, Patrick, Langa, Johannes, Shariffa, Fatin and Pekrula, Sven. "Additive manufacturing of optical components." Adv. Opt. Techn., 2016, pp 293-301. http://adsabs.harvard.edu/abs/2016AdOT....5..293H

KEYWORDS: Optical AM; Optical Additive Manufacturing; Aberration; Lens; Achromat; 3D Graded Index Lens; GRIN 

TECHNOLOGY AREA(S): Info Systems, Battlespace, Weapons 

OBJECTIVE: Develop an Artificial Intelligence (AI) and Machine Learning (ML) based Mission Planner and Management technology that is based on initial analysis of various mission plans to determine where and how AI techniques could significantly benefit the mission planning and management process, including how to validate and verify autonomous performance. 

DESCRIPTION: The National Defense strategy states, “The Department will invest broadly in military application of autonomy, artificial intelligence, and machine learning, including rapid application of commercial breakthroughs, to gain competitive military advantages.” [Ref 4] This topic is clearly aligned with this statement as it seeks to exploit the promising advantages of AI and ML in mission planning. The current Joint Mission Planning System (JMPS) mission planning process may be best described as a hybrid planning activity (i.e., partially accomplished manually by mission planners/pilots and partially accomplished through an automated process). To gain familiarity Reference 1 describes a basic mission planning process. There are a variety of mission types (e.g., Strike, Intelligence Surveillance and Reconnaissance (ISR), manned and unmanned teaming (MUM-T), Multi-Domain Missions (MDM), Close Air Support (CAS), Naval Integrated Fire Control-Counter Air (NIFC-CA)). Each type has unique mission planning components but there are many facets of the planning process that are common to each mission type. These areas should be candidates for automation using AI and ML techniques. In the near future, mission planning will include multi domains that will include air, maritime, land, and space. Many current AI applications focus on human-centric processes. Thus, since part of mission planning is a human-centric activity, increasing the potential for errors. AI technologies would provide tremendous benefit. This effort should determine a method to leverage advantages of AI and ML (to name two of the most often cited, speed and accuracy) and apply it within the mission planning process. Besides defining how to apply AI, the project will also address how to verify and validate the performance of the mission planning with AI, (i.e., what development/technique is necessary to provide planners assurance that the results of AI-generated plans are realistic and/or improved when compared to current planning processes). In addition, aligned with the overall planning process there are two security concerns that will have to be addressed: one being multi-level security due to the fact that some planning data/information is classified at different classification levels; and the other focusing on the highly critical need to protect software and information, thus requiring the need to embed cyber security measures [Refs 9 & 10] Both security concerns should be able to be resolved with AI techniques and should seamlessly and transparently be integrated in the overall planning process. The final step is to simulate mission plans (perhaps not as detailed as described in Reference 4, but somewhat similar) and potentially show how to improve the planning process through ML. Note: It is anticipated that proposers to the topic have some understanding of the mission planning process (relevant mission planning documentation will be made available in Phase I that includes descriptions of different scenarios and software) and should be highly experienced with the development and transition of AI and ML technology, relating to the current state-of-the-art AI and ongoing research as it may be applicable to this topic. 

PHASE I: Determine and identify where and how within the mission planning process AI can make the most significant impact to the process and develop a concept to simulate the overall mission plan with AI and ML. Define a conceptual AI-based planning process that includes multi-level security and cyber security. The Phase I effort will include prototype plans to be developed under Phase II. 

PHASE II: Develop a prototype based on the results of Phase I and demonstrate the capability to verify and validate the mission plan performance with embedded AI. Generate simulated mission plans based on actual Air Tasking Orders. Additionally, show if AI can achieve / identify further improvements in the planning process via self-learning capability. Also address feasibility of dynamic real-time mission replanning during mission execution. 

PHASE III: Finalize the complete AI/ML based mission planning capability and conduct operational testing. Transition technology to a next generation of JMPS and other services in support of mission planning processes. The development will benefit manned / unmanned mission planning that supports commercial delivery companies, especially addressing those that deliver via Unmanned Systems such as Amazon, United Parcel Service, and other organizations and companies that employ Unmanned Air Vehicles as part of their business (e.g., land management). 

REFERENCES: 

1. Menner, W.A. “The Navy’s Tactical Aircraft Strike Planning Process." Johns Hopkins APL Technical Digest, Vol. 18, No.1, 1997. www.jhuapl.edu/techdigest/TD/td1801/menner.pdf; 2. Boukhtouta, A., Bedrouni, A., Berger, J., Bouak, F., and Guitouni, A. “A Survey of Military Planning Systems." Defence Research and Development Canada-Toronto: Toronto, Ontario Canada. www.dodccrp.org/events/9th_ICCRTS/CD/papers/096.pdf; 3. Strong, B.D. "Simulate Tomorrow's Battle with AI." Proceedings Magazine, February 2018, Vol. 144/2/1,380. https://www.usni.org/magazines/proceedings/2018-02/simulate-tomorrow%E2%80%99s-battles-ai; 4. "Summary of the 2018 National Defense Strategy of the United States of America." https://www.defense.gov/Portals/1/Documents/pubs/2018-National-Defense-Strategy-Summary.pdf; 5. Broadway, C. “DoD Official Highlights Value of Artificial Intelligence to Future Warfare." DoD News, Defense Media Activity, April 9, 2018. https://www.defense.gov/News/Article/Article/1488660/dod-official-highlights-value-of-artificial-intelligence-to-future-warfare/; 6. Cummings, M.L. “Artificial Intelligence and the Future of Warfare." Research Paper, International Security Department and US and the Americas Programme, January 2017. Chatham House, The Royal Institute of International Affairs. https://www.chathamhouse.org/sites/files/chathamhouse/publications/research/2017-01-26-artificial-intelligence-future-warfare-cummings-final.pdf; 7. Joint Mission Planning System _Air Force (JMPS-AF). Air Force Programs, pp. 235-236. http://www.dote.osd.mil/pub/reports/FY2011/pdf/af/2011jmps-af.pdf; 8. Tian, Z., Wei, Z., Yaoping, L., and Xianjun, P. "Overview on Mission Planning System." International Journal of Knowledge Engineering, Vol. 2, No. 1, March 2016. http://www.ijke.org/vol2/52-CQ3048.pdf; 9. Davis, S., “Navy Finalizes 8 Cyber Security Standards, Now Available to Industry,” Space and Naval Warfare Systems Command Public Affairs, 2/17/2016, https://www.navy.mil/submit/display.asp?story_id=93151; 10. National Institute of Standards and Technology (NIST) Information Technology Cybersecurity, https://www.nist.gov/topics/cybersecurity

KEYWORDS: Artificial Intelligence; Machine Learning; Multi-Platform Planning; Manned-Unmanned Teaming; Joint Mission Planning System; Naval Open Mission System 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Identify and develop a long-lasting (i.e., mechanically robust, withstand temperatures from -40°F to 135°F without rupture, and have low to zero permeability for 20+ years) dry powder of water-filled microcapsules that can be mixed into viscous pre-polymer liquids without breaking, and remain intact after rubber curing and fuel bladder manufacturing and maintenance, but will break and release their contents when mechanically shocked (i.e., shot with a .50 caliber bullet). Enable the incorporation of the microcapsules into a self-sealing material for fuel bladders solution under development by Naval Air Systems Command (NAVAIR). 

DESCRIPTION: The Navy currently needs to develop robust and long-lasting water-filled microcapsules for a self-sealing material that is activated when it comes into contact with water. For the desired fuel bladder application, no external water source will be required to activate the material after the fuel bladder has been penetrated. Current water-filled microcapsules contain water for days to weeks before the water permeates the microcapsule shell; however, fuel bladders need to be able to self-seal during 20 years of fleet usage. Microencapsulation of liquids is a process used in many industries (e.g., coatings, pharmaceuticals, cosmetics, consumer goods, agriculture); however, microencapsulating water has been a challenge due to the small size of the water molecule that causes it to permeate through the shell of the microcapsule at room temperature. For this project, the microcapsules should contain greater than 80% water by volume as determined by microscopy or a chemical reaction of a ruptured microcapsule and the particle size (in the range of 50-200 microns in diameter) needs to be tightly controlled and nearly monodisperse,(i.e., a coefficient of variation (standard deviation of particle diameter divided by mean particle diameter) of 3% or less) and analyzed with a particle analyzer for each batch of material produced, in order to provide consistent breaking strength from batch to batch (a coefficient of variation (standard deviation of breaking strength divided by mean breaking strength) of 5% or less. The breaking strength range of the microcapsules should be characterized at room temperature (75 degrees F), -40 degrees F, and 135 degrees F by a suitable method, such as Atomic Force Microscopy (AFM) with the load-deflection curves, rupture force and deformation, and Young’s Modulus as significant outputs of the analysis. A large majority of the microcapsules (>99%) must remain intact when exposed to a temperature range of -40 degrees F to 135 degrees F, which is the temperature range of the crashworthy and self-sealing fuel bladder specification MIL-DTL-27422F gunfire test. This may be evaluated by temperature exposure followed by Scanning Electron Microscopy (SEM) and statistical evaluation of the images (i.e., ratio of ruptured to intact microcapsules). The water-filled microcapsules must be resistant to rupture during mixing in viscous (in the range of 100 to 25,000 mPas) pre-polymers, so a lab scale mixing test must be developed where the ratio of ruptured microcapsules before and after mixing is evaluated, again likely through SEM. The microcapsules must be resistant to JP-5 and JP-8 fuel, so their mechanical strength should be evaluated by AFM or other suitable means after exposure to fuel. The composite of the microcapsules with the cured polymer will need to withstand lab scale handling tests including a fold over test (180-degree bend) to simulate a bladder being folded during installation into an aircraft according to MIL-DTL-27422F paragraph 4.4.5.7 Stress Aging; an Impact Resistance drop test (1 lb. blunt chisel dropped from several heights) to evaluate small mechanical shocks according to MIL-DTL-27422F Paragraph 4.5.6 Impact Resistance; and quasi-static compression (up to 300 lbs./inch) to simulate maintainers walking and crawling on fuel bladders. An accelerating aging test (see MIL-STD-810G section 520.3 Temperature, Humidity, Vibration, and Altitude and section 524 Freeze/Thaw) will need to be developed to determine the likelihood of the microcapsules surviving in the fuel bladder for 20+ years. This will likely need to consist of thermal cycling and mechanical bending and compression cycling tests, while looking for activation of the microcapsule/polymer composite (i.e., the self-sealing material). An evaporation test will need to be performed by monitoring and tracking the weight loss of several ounces of microspheres in a drying oven over the course of weeks to months to determine a water evaporation rate. The microcapsule/polymer composite will need to be incorporated into a MIL-DTL-27422F Phase I test cube to undergo gunfire testing. Since the construction of a fuel bladder test cube is not a trivial task, it is recommended that the proposer partner with a fuel bladder manufacturer in the final stages of this project. 

PHASE I: Define and develop a concept for a microcapsule that will meet the Description above and determine the feasibility of producing a prototype both at lab scale and on a large scale. Develop concepts for robustness (mechanical, thermal, chemical), longevity (accelerated aging and evaporation), and shock tests. Develop a concept for incorporating the microcapsules into a polymer matrix. The Phase I effort will include prototype plans to be developed during Phase II. 

PHASE II: Develop, on a lab scale, prototypes of the microcapsule and microcapsule/polymer composite based on concepts developed in Phase I. Implement the test concepts using them as quality checks on the products in the lab scale process. Refine the tests, as required. Once the lab scale process for producing the microcapsules and the microcapsule/polymer composite and all of the tests are mature, generate a concept for large scale production of the microcapsules and microcapsule/polymer composite along with a concept for integration of the microcapsule/polymer composite into a fuel bladder. 

PHASE III: Produce fuel bladders or partner with another company that already produces fuel bladders so that the microcapsule/rubber composite self-sealing layer may be evaluated in a Phase I (not STTR Phase I) fuel bladder cube gunfire test according to MIL-DTL-27422F. After passing the gunfire test, incorporate the self-sealing technology into a fuel bladder production process to bring the technology to the fleet. Successful development of this technology could benefit fuel bladder manufacturers by giving them the ability to meet the fuel bladder self-sealing requirements. The microcapsules could be used in the pharmaceutical and consumer products industries for encapsulating aqueous medicines, activating water curing adhesives like cyanoacrylate (superglue), and self-healing coatings. The self-sealing layer that incorporates the water filled microcapsules can be used in other self-sealing applications, including pneumatic tires and inflatable rafts and life vests. 

REFERENCES: 

1. Atkin, R., Davies, P., Hardy, J., & Vincent, B. “Preparation of Aqueous Core/Polymer Shell Microcapsules by Internal Phase Separation.” Macromolecules, September 25, 2004, pp. 7979-7985. https://pubs.acs.org/doi/pdf/10.1021/ma048902y; 2. Datta, S. S., Abbaspourrad, A., Amstad, E., Fan, J., Kim, S.-H., Romanowsky, M., Shum, Ho Cheung, Sun, Bingjie, Utada, Andrew S., Windbergs, Maike, Zhou, Shaobing, Weitz, D. A. “25th Anniversary Article: Double Emulsion Templated Solid Microcapsules: Mechanics and Controlled Release.” Advanced Materials, Volume 26, Issue 14, April 9, 2014, pp. 2205-2218. https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201305119; 3. Olvera-Trejo, D., & Velasquez-Garcia, L. “Additively Manufactured MEMS Multiplexed Coaxial Electrospray Sources for High-Throughput, Uniform Generation of Core-Shell Microparticles.” Lab On a Chip, Issue 26, 2016, pp. 4121-4132.; 4. Sun, Q., & Routh, A. F. “Aqueous Core Colloidosomes with a Metal Shell.” European Polymer Journal, Volume 77, April 206, pp. 155-163. https://www.sciencedirect.com/science/article/pii/S001430571630043X; 5. Xi Lu, A., Oh, H., Terrell, J., Bentley, W., & Raghavan, S. “A new design for an artificial cell: polymer microcapsules with addressable inner compartments that can harbor biomolecules, colloids or microbial species.” Edge Article: Chemical Science, 8, 2017, 6893-6903. https://pubs.rsc.org/en/content/articlehtml/2017/sc/c7sc01335c; 6. Yin, W., & Yates, M. “Development of Novel Microencapsulation.” Doctoral Dissertation, University of Rochester: Rochester, New York, 2009. https://urresearch.rochester.edu/fileDownloadForInstitutionalItem.action?itemId=7422&itemFileId=14366; 7. MIL-DTL-27422D, DETAIL SPECIFICATION FOR THE TANK, FUEL, CRASH-RESISTANT, BALLISTIC-TOLERANT, AIRCRAFT (30 JAN 2007) [SUPERSEDING MIL-T-27422B(1)] http://everyspec.com/MIL-SPECS/MIL-SPECS-MIL-DTL/MIL-DTL-27422D_20366/; 8. MIL-STD-810G, DEPARTMENT OF DEFENSE TEST METHOD STANDARD: ENVIRONMENTAL ENGINEERING CONSIDERATIONS AND LABORATORY TESTS (31 OCT 2008) http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL-STD-810G_12306/

KEYWORDS: Microcapsule; Microsphere; Microencapsulation; Dry Water; Nanosphere; Powdered Water 

TECHNOLOGY AREA(S): Air Platform, Materials 

OBJECTIVE: Design and develop methodologies to fabricate a three-dimensional (3D) braided composite part, specifically those with solid cross-sections and complex geometries. 

DESCRIPTION: The attraction of 3D braided architecture is that it is inherently damage tolerant and can produce near net-shape products; however, these improvements usually come with a stiffness penalty. Additionally, there are limitations on the geometries that can be braided near-net shape. This is particularly true for solid cross-sections where the geometry and shape change along the braiding axis. Conventionally, complex shapes are produced either by over braiding on an insert or by machining an oversized braided composite. The first approach results in a weak interface between the insert and the braid. The second approach is not a near net-shape and results in increased scrap and a weaker structure, resulting from the cut fibers on the surface. Innovations are sought in braiding technology that can address these deficiencies and successfully produce complex rotorcraft components. In addition to technical maturity, scalability of the approach, and automation of the process are important. These criteria will be used during the evaluation process. 

PHASE I: Define and develop a concept for an innovative braiding methodology and establish the feasibility of the methodology to fabricate a rotorcraft airframe or rotor component. Feasibility can be established by fabricating coupons that are representative of geometry and cross-section changes of a rotorcraft component. Candidate components may include, but are not limited to, fuselage frame elements, rotor hub, and rotor yoke sub-assemblies. The Phase I effort will include prototype plans to be developed under Phase II. In choosing the components, please refer to JSSG-2006 [Ref 3] and AR-56 [Ref 2] for overarching requirements for Navy rotorcraft structures. 

PHASE II: Demonstrate the production methodology by producing a prototype component in a lab or live environment. 

PHASE III: Finalize and mature the technology for transition and insertion into Future Vertical Lift (FVL) for production fuselage or rotor hub components. The technology will be highly applicable to commercial aviation for reducing production costs by replacing metallic airframe structures with composites. 

REFERENCES: 

1. Chou, T.-W. and Ko, F. Textile Structural Composites. Elsevier Science: Amsterdam, 1988. https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.19890011016; 2. Airworthiness Certification criteria (AR-56 Structural Design Requirements (Helicopters)). Department of Defense, 2004. http://everyspec.com/MIL-HDBK/MIL-HDBK-0500-0599/MIL_HDBK_516A_2069/; 3. Joint Service Specification Guide Aircraft Structures. Department of Defense, 1998. http://everyspec.com/USAF/USAF-General/JSSG-2006_10206/; 4. Kyosev, Y. Advances in Braiding Technology: Specialized Techniques and Applications. Elselvier: Cambridge, 2016. https://www.sciencedirect.com/science/book/9780081009260; 5. Lam, Hoa. “3-Dimensionally Braided Ceramic Matrix Composite Fastener.” Defense Manufacturing Conference. (Uploaded to SITIS 04/18/2019)

KEYWORDS: Composites Manufacturing; Near Net Shape Manufacturing; 3D Braiding; Rotorcraft Airframe Structure; Composite Hub; Composite Yoke 

TECHNOLOGY AREA(S): Materials, Human Systems 

OBJECTIVE: Develop a non-destructive testing capability to detect when the strength of webbing is no longer capable of withstanding the load for which it is designed. 

DESCRIPTION: A capability is needed to detect when the load-bearing strength of a webbing has decreased into an unsafe zone. The strength of webbing is degraded with each use, and the degradation depends upon the webbing material, and the exposure to environmental factors. Because degradation is typically silent and invisible, unexpected failure during an emergency is a hazard that the Navy wishes to avoid. A non-destructive way to detect degradation has long been sought by the narrow fabrics industry. The demand is there, but the technology is lacking. Incorporating multiple indicator technologies rather than relying upon a single technology is an approach that may be more achievable than expecting one technology to detect every kind of failure mode. Incorporating load indicators in the load-axis of the structure without affecting the load-bearing capability is yet another challenge. Embedding sacrificial visual wear indicators, like those used in road tires, in the webbing’s binder or marker yarns could indicate excessive abrasion. A dye that fades predictably and measurably under ultraviolet (UV) exposure or ozone may be another approach. Solid state mechanochromic luminescent dyes could potentially indicate when a load threshold has been breached. The goal of this STTR effort is to incrementally develop an indicator integral to a common webbing type or develop a portable test/inspection method that can be used on a common webbing type end-item in situ (e.g., on a restraint seat harness installed in the aircraft cockpit). Current failure detection methods are limited to visual inspection by the naked eye using somewhat vague and incomplete criteria. Reference 1 directs the parachutist to check the webbing “for damage” and the harness for signs of “completeness, cuts, broken stitching, acid and signs of chafing and wear.” The Parachute Industry Association [Ref 2] states, “Any cuts, nicks or heavy abrasion to webbing should be shown to a certified rigger before the next jump.” Direction to check for loss of pliability or color change or loss is missing, as is direction to check specific areas of webbing exposed to flex fatigue and hardware surfaces, such as friction adjusters in buckles. Cascading failure begins on the molecular level with a weakened chemical structure [Ref 3]. Degradation of the fiber follows. Mechanical stress can cause failures of the yarn comprising these weakened fibers and Hearle, Lomas, and Cooke in Chapter 38 [Ref 4] show scanning electron microscope images of the filament fractures of ejection seat webbing yarns attributed to shear loading, flex fatigue, and friction from hardware components. The next step is failure of the end-item itself. Accelerated aging harness testing that excluded mechanical degradation showed that aged webbing tended to break before the stitched seam more frequently with a corresponding loss in tensile strength [Ref 5]. As the sewing thread is subject to the same degradants as the webbing, stitches were observed to fail before the webbing did, but less frequently. There is currently no standard method to conduct surveillance testing of webbing. Of the very few surveillance testing studies that have been published, the criteria for accelerated aging can vary greatly by the purpose of the end item. For example, nylon is known to be degraded by exposure to UV radiation and a combination of high heat and humidity, and therefore those conditions are usually included in accelerated aging testing of ejection seat webbing. On the other hand, even though ejection nylon webbing is vulnerable to abrasion from blowing sand/dirt, ejection seat testing typically excludes that degradant because the closed cockpit shields the webbing from exposure. Military helicopter seat harnesses and aircraft tie-downs, however, always include blowing sand and dust, and ship exhaust on carriers as degradants due to their exposed conditions. Reference 5 identifies static tensile strength as the main variable, and interpreted strength loss by age trends to determine the probability of maintaining 1.5/1 margin of safety factor over three years. Small-scale dynamic testing and static testing of elongation by age was used by the European Aviation Safety Agency [Ref 6]. The Code of Federal Regulations provides pass/fail criteria in terms of allowed percentage loss for automotive seat belt assemblies, using abrasion, UV exposure, micro-organisms as independent variables, and elongation and breaking strength as dependent variables. Proposals for Phase I should include a background section with explanatory figures describing the basic principles of the proposed technology concept, and publications or other references that outline the application being considered. It is recommended, but not required, that partnering with original equipment manufacturers be considered. 

PHASE I: Demonstrate feasibility with an analysis that supports the proposed technology concept. Provide experimental work that demonstrates that the indicating technology is capable of detecting a 25 percent decrease in strength and elongation. Include a 3-tiered work breakdown structure with Gantt chart of Phase I design activities, and include make/break criteria and events. Provide Technical Performance Measures for Government review and approval that will be tracked throughout Phases I-III. The Phase I effort will include prototype plans to be developed under Phase II. 

PHASE II: Incrementally develop the strength loss indicator technology. Demonstrate the technology using PIA-W-4088 Type VII Class I webbing [Ref 8], which is commonly used in both commercial and military applications, or another webbing with similar width, thickness and strength properties. Include a 3-tiered work breakdown structure with Gantt chart of Phase II design activities, and include make/break criteria and events. Track performance against agreed-upon Technical Performance Measures quarterly. Develop quality assurance measures. Demonstrate the capability of the prototype on, or incorporated in, five sets of ten webbing test articles plus one control set conditioned per MIL-STD-810 procedures [Ref 9]: Set 1 should be exposed to UV radiation; Set 2 to combined high heat and humidity; Set 3 to impact cycling; Set 4 to fluid contaminants, salt fog, blowing sand/dust, and stack gas exposure; and Set 5 to all four (in sequence, as laboratory concomitant exposure is not yet possible). Produce a final Phase II report that includes raw data, photography and/or video recording, data recording sheets, documentation of test devices (manufacturer, model, serial, accuracy, calibration status) and test reports written in accordance with any specified standards. Develop a performance specification to document the Phase II prototype technology. 

PHASE III: Finalize the developed strength loss indicator technology for webbing in performance specification and engineering drawings in accordance with military standards. Develop and perform required operational testing, document the quality assurance test program in accordance with industry best practices, and transition into military and commercial webbing markets. This technology may benefit the private sector in such markets as industrial fall arrest harnesses and tethers, commercial aircraft and automotive seat harnesses, and recreational airborne sports such as skydiving, hang-gliding, and parasailing. 

REFERENCES: 

1. Parachute Rigger Handbook. Federal Aviation Administration, Flight Standards Service, Washington, DC, 2015 https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/prh_change1.pdf; 2. “Technical Standard 135: Performance standards for personnel parachutes and components, Rev 1.4 (PIA TS 135).” Parachute Industry Association, 2010. https://www.pia.com/piapubs/TSDocuments/TS-135v1.4.pdf; 3. Segars, R.A. “The degradation of parachutes: age and mechanical wear (NATICK/TR-92-035).” http://www.dtic.mil/dtic/tr/fulltext/u2/a252243.pdf; 4. Hearle, J.W.S, Lomas, B., and Cooke, W.D. Atlas of Fibre Fracture and Damage to Textiles (2nd ed). Woodhead Publishing: Cambridge, UK, 1998. https://www.sciencedirect.com/science/book/9781855733190; 5. Maire, R. and Wells, R.D. “Engineering evaluation of age life extension, T-10 harness, risers, and T-10 troop chest reserve parachute canopies (TR-72-59-CE).” United States Army Natick Laboratories, March 1972. http://www.dtic.mil/dtic/tr/fulltext/u2/742668.pdf; 6. Robinson, L., Atkin, C.J., Payne, T., Harper, C., and Frost, G. “Seat Belt Degradation, Phases I and II (EASA.2010.C21/EASA.E2.2011.C11 SEBED).” https://www.easa.europa.eu/sites/default/files/dfu/SEBED%20Report_Final_5-2010.pdf; 7. Seat belt assemblies, 49 CFR §571.209 (2004). https://www.law.cornell.edu/cfr/text/49/571.209#b; 8. “Webbing, textile, woven nylon (PIA-W-4088 F).” Parachute Industry Association, 2013. http://quicksearch.dla.mil/qaDocDetails.aspx?ident_number=213689; 9. “Environmental Engineering Considerations and Laboratory Tests (MIL-STD-810G).” Department of Defense, 2008. http://quicksearch.dla.mil/qaDocDetails.aspx?ident_number=35978

KEYWORDS: Textiles; Webbing; Service-Life; Life Extension; Non-Destructive-Testing-And-Inspection; NDTI; Strength Loss 

TECHNOLOGY AREA(S): Air Platform, Materials, Weapons 

OBJECTIVE: Develop and demonstrate a physics-based erosion model for gas-turbine grade ceramic matrix composites (CMCs). 

DESCRIPTION: CMCs are currently being considered for use in hot-section hardware of advanced aero engines with goals of increased performance and efficiency. Concerns exist regarding the degradation of CMCs due to life-limiting phenomena associated with thermal, mechanical, chemical, and environmental effects. Of particular concern is erosion by small particles such as sand, dust, and other fine erosive objects ingested into hot-sections of engines. Since CMCs are brittle in nature and some sections of CMC components such as airfoils are in a thin configuration, erosion generates a varying degree of damage from localized micro-fracture to significant material removal, depending on the severity of erosion events. Consequently, erosion in CMC hardware can result in a reduction in load-carrying capacity, a premature component life, and a loss of related functions. Significant science and technology activities have modeled erosion behavior in metallic, polymeric, and coating materials systems [Refs 1-3]. However, despite its importance and demand, to date no pertinent model exists able to describe erosion phenomena of CMCs. Erosion in CMCs has shown to be very complex due to the random and violent nature of erosion events coupled with the materials’ architectural and constituent complications [Refs 4,5]. As a consequence, an emerging need exists to develop an innovative physics-based erosion model for CMCs. The model, at a minimum, is to be able to predict the rate and shape of material removal with respect to type of materials for given erosion conditions. The approach is also expected to leverage overall experimental and fabrication efforts/iterations and to contribute to the improvement of the design of CMCs that are more durable and reliable against erosion. In general consideration, but not limited, target materials are gas-turbine grade CMCs, erosive particles are silica or ceramic-based and random in shape with varying sizes of 50-200 micrometers, and particle velocities are in a range of Mach 0.2 to 2. 

PHASE I: Design and develop an initial erosion model concept and demonstrate feasibility for the CMC material systems. The Phase I effort will include prototype plans to be developed under Phase II. 

PHASE II: Fully develop and optimize the approach formulated in Phase I. Demonstrate and validate the approach using pertinent data obtained from selected materials systems under appropriate erosion conditions. 

PHASE III: Perform validation and certification testing. Transition the approaches to CMC propulsion applications for platforms such as Variable Cycle Advanced Technology (VCAT), Versatile Affordable Advanced Turbine Engines (VAATE), and other advanced Naval engines. CMC propulsion materials have great potential to the civilian aerospace engine applications and are being transitioned in some areas. The proposed erosion technology development will benefit the private sector in their efforts to enhance the overall durability and reliability of CMC hardware. Industries such as land-based or marine gas turbine engine industries, automotive industry, and material developers/designers would benefit from successful technology development. 

REFERENCES: 

1. Gopferich, A. and Langer, R. “Modeling of Polymer Erosion.” Macromolecules, 26 (16), 1993, pp. 4105-4112. https://pubs.acs.org/doi/pdf/10.1021/ma00068a006; 2. Grant, G. and Tabakoff, W. “Erosion Prediction in Turbomachinery Resulting from Environmental Solid Particles.” Journal of Aircraft, 1975, pp. 471-478. https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/ADA016084.xhtml; 3. Kedir, N., Gong, C., Sanchez, L., Presby, M., Kane, S., Faucett, C., and Choi, S. “Erosion in Gas-Turbine Grade Ceramic Matric Composites (CMCs).” Journal of Engineering for Gas Turbines and Power, 2018. http://gasturbinespower.asmedigitalcollection.asme.org/article.aspx?articleid=2688315; 4. Wellman, R. and Nicholls, J. “A Monte Carlo Model for Predicting the Erosion Rate of EB PVD TBCs.” Wear, Volume 256, Issues 9-10, pp. 889-899 (1-38). https://pdfs.semanticscholar.org/8fa0/5107f86ecd1ea036a8374085eec55dbe9173.pdf?_ga=2.16680245.246856754.1532002677-142685204.1531247380

KEYWORDS: Ceramic Matrix Composites; CMCs; Gas-Turbine Grade CMCs; Erosion; Erosion Modeling; Erosive Particles; Erodent 

TECHNOLOGY AREA(S): Materials 

OBJECTIVE: Develop a modeling tool to rapidly predict the surface finish of metal additively manufactured (AM) parts as a function of AM process parameters and to determine AM processing and path planning to achieve optimal surface finish. 

DESCRIPTION: Additive Manufacturing (AM) technologies, such as Laser Powder Bed Fusion (LPBF) process, have become increasingly important for the rapid production of industrial products. However, AM processes also pose challenges with associated features, such as defects and inherent surface roughness, which can degrade the fatigue performance. A significantly lower endurance limit was reported for specimens with inherent surface roughness compared to polished ones [Ref 7]. Thus, the surface finish can influence the fatigue performance due to multiple stress concentrations. High cycle fatigue properties are especially dominated by surface finish [Ref 3]. There are several factors that can affect the surface finish of an AM part, such as powder distribution, energy density, build orientation, powder morphology, energy source, scan speed, hatch width, and staircase effect [Ref 4]. Although a fine powder granulation generally leads to better densities and surface qualities than a coarser material, the distribution of particle sizes can be even more important [Ref 4]. Some more in-depth physical phenomena, such as the balling process, can be commonly found as surface defects in which large drops, with size exceeding laser spot diameter, quickly spread out in droplets [Ref 6]. Geometric defects such as elevated edges disrupt the build process and distort subsequent surfaces [Ref 2]. The presence of overhangs or upwards facing surfaces produce different surface finish characteristics [Ref 2]. Although secondary processes, such as machining, may overcome the surface finish issue, the non-line-of-sight surfaces resulting from specific part geometries may not be accessible for machining. A multi-physics modeling tool is needed to rapidly predict, in minutes to hours for a desktop environment, the surface finish of a metal AM part and to provide a strategy in AM processing/path planning to achieve the minimum roughness surface finish. There have been some efforts to model the surface finish of AM parts, such as modeling the roughness profile for the Fused Deposition Modeling (FDM) technology. This allowed the calculation of the roughness parameters as a function of the layer thickness and the deposition angle [Ref 1]. Another effort was carried out to describe the effects of partially bonded particles on the surface of an LPBF part [Ref 5], and work was also done to predict the roughness obtainable on AlSi10Mg processed by LPBF, taking into account the staircase effect, and the defects typical of this aluminum (Al) alloy. However, these models only address a portion of the issues affecting a part’s surface finish. The Navy is seeking a more developed tool that captures the process parameters used by the machine. This modeling tool should be able to predict and optimize the surface finish, preferably through implementation of machine learning or another rapid convergence technique, based on key parameters such as, but not limited to, the part geometry, material properties (e.g., powder composition, particle size distribution, morphology), and initial AM processing parameters (e.g., powder distribution, energy density, build orientation, energy source, scan speed, hatch width, layer thickness, processing conditions). Users should be provided with an updated set of process parameters to achieve the optimal surface finish. Demonstration of the tool’s predictive and optimization capabilities should be on Ti-6Al-4V printed specimens. The tool should be designed to provide process parameters compatible with EOS powder bed machines. 

PHASE I: Demonstrate the feasibility of a multi-physics modeling tool to predict the surface finish based on key process parameters. Predict the surface finish of some representative geometric features (overhangs, holes, radii, etc.) for typical LPBF processing. Compare the predicted surface finish of the test cases by printing Ti-6Al-4V samples to show the effectiveness of the model’s prediction capability. The Phase I effort will include prototype plans to be developed under Phase II. 

PHASE II: Develop a full-scale multi-physics modeling prototype to rapidly optimize the surface finish based on various process parameters, including, but not limited to, powder distribution, energy density, build orientation, material properties, powder particle size distribution and morphology, energy source, scan speed, hatch width, layer thickness, part geometry, and processing conditions. Demonstrate the solution(s) in a real-world AM processing scenario and its possible transition into both military and commercial applications. Note: No Government test facility should be needed. 

PHASE III: Develop standalone compliance with major powder bed machines (e.g., EOS, Renishaw, Concept Laser). The benefits in surface finish from this topic will directly benefit the aerospace, automotive, and energy industries utilizing AM by reducing the amount of post-process machining necessary to meet surface finish requirements for high performance parts. 

REFERENCES: 

1. Boschetto, A. and Giordano, V. “Modelling Micro Geometrical Profiles in Fused Deposition Process.” The International Journal of Advanced Manufacturing Technology, 2012, pp. 945-956. https://link.springer.com/article/10.1007/s00170-011-3744-1; 2. Grasso, M. and Colosimo, B. “Process Defects and In Situ Monitoring Methods in Metal Powder Bed Fusion: A Review.” IOP Publishing Ltd., 2017. http://iopscience.iop.org/article/10.1088/1361-6501/aa5c4f/meta; 3. Greitemeier, D., Dalle Donne, C., Syassen, F., Eufinger, J., and Melz, T. “Effect of Surface Roughness on Fatigue Performance of Additive Manufactured Ti-6A1-4V.” Journal of Materials Science and Technology, 2016, pp. 629-634. https://www.tandfonline.com/doi/full/10.1179/1743284715Y.0000000053?scroll=top&needAccess=true; 4. Spiering, A., Herres, N., and Levy, G. “Influence of the Particle Size Distribution on Surface Quality and Mechanical Properties in AM Steel Parts.” Rapid Prototyping Journal, 2011, pp. 195-202. https://www.emeraldinsight.com/doi/pdfplus/10.1108/13552541111124770; 5. Strano, G., Hao, L., Everson, R., and Evans, K. “Surface Roughness Analysis, Modelling and Prediction in Selective Laser Melting.” Journal of Materials Processing Technology, 2013, pp. 589-597. https://www.sciencedirect.com/science/article/pii/S0924013612003366; 6. Tolochko, N., Mozzharov, S., Yadroitsev, I., Laoui, T., Froyen, L., Titov, V., and Ignatiev, M. “Balling Processes During Selective Laser Treatment of Powders. Rapid Prototyping Journal, 2004, pp. 78-87. https://www.emeraldinsight.com/doi/pdfplus/10.1108/13552540410526953; 7. Wycisk, E., Solbach, A., Siddique, S., Herzog, D., Walther, F., and Emmelmann, C. “Effects of Defects in Laser Additive Manufactured Ti-6A1-4V on Fatigue Properties.” 8th International Conference on Photonic Technologies LANE 2014, Physics Procedia 56 (2014), pp. 371-378. https://core.ac.uk/download/pdf/82733008.pdf

KEYWORDS: Surface Finish; Surface Roughness; Additively Manufacturing; AM; Modeling; Powder Bed Fusion 

TECHNOLOGY AREA(S): Info Systems 

OBJECTIVE: Develop a universal Sensor Things Application Programming Interface (API) that enables systems to utilize data from all current and future sensors without requiring new development. 

DESCRIPTION: Today’s undersea environment is experiencing a proliferation of sensors, such as high-end military towed arrays, commercial side-scan SONARs on unmanned vehicles, disposable sonobuoys, and commodity temperature sensors. This is similar to the proliferation of sensors comprising the Internet of Things. Examples are sensors in a basic smartphone Global Positioning System (GPS) and smart traffic control capabilities, which utilize data gathered from sensors displayed on a user-friendly Graphical User Interface (GUI) for the user to visualize the data. The military sensors and Internet of Things sensors all have a basic common concept –sense something measured at some point in geospatial and temporal space and display. While sensors are proliferating, a lack of standardization requires that the Navy continually re-develop and re-implement software to handle new sensors. This technology addresses the need to streamline the incorporation of new and improved sensors into networked systems. These new sensors provide similar data, causing a recurring cost and effort to maintain the software. The focus of this effort is to determine the feasibility of newly formalized Sensor Things Application Programming Interface (API) standard by which such data can be provided for the AN/UYQ-100 Undersea Warfare Decision Support System (USW-DSS). In response to the rise of the Internet of Things, along with the growing need to provide a common API through which sensors can report measurements in time and space, the Open Geospatial Consortium (OGC) has recently published the Sensor Things API. No common standard by which different types of sensors can report their measurements existed prior to this standard. As such, inclusion of data from a new sensor into a system required additional software development; specific logic unique to that sensor; and associated cost and schedule implications. Development of the universal sensor API will allow for data from new sensors to be integrated into USW-DSS (and other systems) to address this challenge and enable the integration of new sensors without requiring new development. The Navy seeks an innovative implementation of a Universal Sensor Things API for the AN/UYQ-100 USW-DSS focused on the undersea domain and the heterogeneous types of data. Future sensors will likely acquire and report these data sets. The Navy will also require a process for generating or obtaining test data adequate to support testing. Design efforts include describing the proposed technology stack for use on the server-side. Initial efforts would be expected to quantify expected performance of the proposed API implementation in terms of anticipated data throughput for integration as well as similar expected performance for queries. Finally, a successful effort would provide a plan to utilize real sensors or sensor mockups to verify the performance of the API implementation. Implementation of the Sensor Things API offers standardization to a common API. This effort seeks a design for an innovative Universal Sensor Things API that utilizes best open source components and technologies to allow the implementation to scale from a laptop to a large computing cluster, demonstrating an ability to integrate data at various rates and diverse data payloads. This design should also consider how evolving security threats can be addressed by this universal API. Since the Navy requires a scalable implementation which could be integrated into multiple programs with different hardware footprints, a successful design would specifically allow for both vertical scalability (fewer servers, with more resources) and horizontal scalability (more servers, with less individual capability). A critical component of this effort is determining which existing open-source technologies to leverage (i.e., the “technology stack”) to develop a scalable, re-usable Sensor Things API. This should at minimum support the development of nominal anticipated performance characteristics of an analogous implementation, specifying parameters such as maximum number of data feeds and rate of data ingest. Refinement of the proposed analogous implementation will be provided to the awardee by the Government. 

PHASE I: Develop a concept for a Universal Sensor Things API for the AN/UYQ-100 USW-DSS in accordance with the Description of this topic. Demonstrate the feasibility of the concept through modeling and simulation. Develop a Phase II plan. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a solution in Phase II. 

PHASE II: Develop and deliver a prototype Universal Sensor Things API based on the results of Phase I and the Phase II Statement of Work (SOW). Ensure that this prototype utilizes a design and implementation process that meets the parameters described in the Description. Include iterative development and testing of methods. Use ongoing benchmarking and analysis of implementation performance to meet the performance goals described in the Phase II SOW. 

PHASE III: Support the Navy in transitioning the Universal Sensor Things API into the AN/UYQ-100 USW-DSS platform using the Program Office software transition process. Finalize the technology by demonstrating the capability needs (listed in the Description) during a testing evaluation event to determine the effectiveness of the Universal Sensor API in the Navy’s sensor interface development environment. Support the Navy for test and validation in accordance with the peer review processes and test and evaluation required to support integration into the AN/UYQ-100 USW-DSS software baseline. This technology has significant potential for commercial application, including oil, mineral, and gas industries; fishing industries; and weather forecasting, which could all benefit substantially from additional data about measured ocean characteristics. 

REFERENCES: 

1. Morgan, Jacob. “A Simple Explanation of ‘The Internet of Things.” Forbes Magazine. 13 May 2014. https://www.forbes.com/sites/jacobmorgan/2014/05/13/simple-explanation-internet-things-that-anyone-can-understand/#2c5968a41d09; 2. “AN/UYQ-100 Undersea Warfare Decision Support System (USW-DSS).” Official Navy Website. 24 January 2011. http://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=324&ct=2; 3. Liang, Steve. “OGC SensorThings API Part 1: Sensing”. Open Geospatial Consortium, 26 July 2016. http://docs.opengeospatial.org/is/15-078r6/15-078r6.html; 4. Seffers, George. “NATO Studying Military IoT Applications.” Signal Magazine, 1 March 2017. https://www.afcea.org/content/Article-nato-studying-military-iot-applications

KEYWORDS: Open Geospatial Consortium; Standardization Of Sensors; Universal Interface; Open-source; Technology Stack; USW-DSS AN/UYQ-100 

TECHNOLOGY AREA(S): Human Systems 

OBJECTIVE: Develop a Human Machine Interface (HMI) for three-dimensional (3D) Field of Light Display (FoLD) visualization systems to reduce cognitive burden and enable 3D collaborative environments. 

DESCRIPTION: As the Navy continues to reduce manpower requirements associated with operating ever-increasing technologically complex systems, new methods that enable natural and intuitive interaction with 3D data are required to reduce overall operator workload and to enhance situational awareness. Operators who cannot quickly access and interpret data are prone to errors ranging from missing critical data during tactical situations, to making judgments based on incorrect information. Developing an optimized capability to engage with 3D information in a high-stress environment will allow the warfighter to increase task accuracy, reduce response time, and increase overall situational awareness. Field of Light Display (FoLD) systems are a class of autostereoscopic displays that provide 3D aerial visualizations without head tracking or eyewear (which impedes natural human vision), allowing for natural communication and collaboration among decision makers. In addition, FoLD systems provide 3D visualization without regard to viewer position or gaze direction and present correct imagery perspective to all viewers within the display’s projection frustum. Several studies highlight the advantages of 3D light-field holograms in enabling better mission planning or medical training. [Ref 1, 2, 3]. By presenting the 3D scene in a natural manner, the cognitive load on the viewer(s) is decreased and the ability to make decisions based on complicated information grows. Deconflicting prioritization in the various theaters of air, surface, and subsurface proves challenging due to the 3D nature of the data and its subsequent visualization on two-dimensional (2D) displays. Currently, the operator is required to divert attention from their tasks to click through multiple menus to obtain such metadata as ascending or descending attributions, latitude and longitude, trajectory, and asset state. FoLD technologies provide several novel capabilities for reducing cognitive load on operators performing identification (ID) during volume searches. However, the way in which a user interacts with this 3D information requires more investigation to determine optimal human/FoLD interface. Much of the FoLD research to date has focused on the 3D projection aspects of producing a 3D aerial image. Of equal importance is the manner in which humans interact with the 3D image to make command level decisions. For all FoLD systems, the 3D aerial image is ethereal and lacking both tactile and kinesthetic feedback. In some FoLD systems, all or part of the 3D image may be enclosed behind a transparent enclosure or cover glass. The Navy requires a mechanism for interacting with emerging FoLDs that will provide an optimized ability for the user to engage with 3D information in a high-stress environment. These types of environments can be replicated by laboratory testing of current operator display system tasks/scenarios (ascending or descending attributions, latitude and longitude, trajectory, and asset state) which adhere to the full spectrum of the Combat Information Center (CIC) and/or watch stander environments. The proposed solution will also need to consider the resulting physical and psychological effects on the user. Understanding how humans process information through cognitive load theory, human computer interaction (HCI), and multi-modal learning should be a part of the design process for a meaningful solution. Performance will be measured by assessing task completion times, user cognitive load analysis, and physical impacts of the proposed system. This innovation must be a novel and practical solution to providing interactivity with 3D imagery produced by a FoLD system. The solution must allow accurate and repeatable interactivity and operation within the view volume. The ability to select, rotate, scale, translate, and otherwise manipulate 3D objects within the 3D scene is required. The research and development effort may include 3D pucks, trackballs, mice, wands, gloves, hand position sensors, video game controllers, or any other comparable technology. The solution must execute with little to no impact on the computational performance of the combat system environment under test. The proposed Human Machine Interface (HMI) should work with a variety of FoLD implementation independent technologies and complex tasks, support ruggedization for use in harsh environments, allow for natural and intuitive operation (minimize training) and support multiple simultaneous users. 

PHASE I: Provide a concept for a FoLD HMI for interacting with a 3D image. The concept must show that it can feasibly meet the requirements of the Description. Establish feasibility through modeling and demonstration of the HMI concept. Develop a Phase II plan which includes human subject testing. In preparation for the human subject testing to take place during Phase II, Institutional Review Board (IRB) approval must be acquired during the Phase I. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II. 

PHASE II: Develop and deliver a FoLD HMI interactive device prototype that is capable of demonstrating the implementation and integration into the combat system environment for testing and evaluation. Demonstrate accuracy, repeatability, and functionality, adhering to the requirements outlined in the Description requirements. Perform a demonstration at a Land Based Test Site (LBTS), which represents an unclassified simulation environment, provided by the Government. 

PHASE III: Support the Navy in transitioning the technology to Navy use and support further refinement and testing of the HMI's functionality following successful prototype development and demonstration. Upon capability demonstration and quantifiable test results, direct the focus toward the transition and integration of the HMI with the emerging FoLD Systems for a 2024 technical insertion as a component of the Aegis Combat System. This HMI device will allow users to interact with data in a 3D environment naturally and intuitively and greatly enhance pre-operative planning and post-operative reviews by surgeons, medical students, and hospital staff. 

REFERENCES: 

1. Sven Fuhrmann, N. J. “Investigating Geospatial Hologram for Special Weapons and Tactics Teams." Cartographics Perspectives, 2009. http://cartographicperspectives.org/index.php/journal/article/viewFile/cp63-fuhrmann-et-al/214; 2. Hackett, M. “Medical Holography for Basic Anatomy Training.” Orlando: Interservice/Industry Training, Simulation and Education Conference (I/ITSEC), 2013. https://cdn2.hubspot.net/hub/151303/file-476620026-pdf/docs/medical_holograms_whitepaper.pdf; 3. Burnett, Thomas. “Light-field Display Architecture and the Challenge of Synthetic Light-field Radiance Image Rendering.” SID. 2017. https://www.researchgate.net/publication/318144885_61-1_Invited_Paper_Light-field_Display_Architecture_and_the_Challenge_of_Synthetic_Light-field_Radiance_Image_Rendering

KEYWORDS: FoLD; 3D Light-field Holograms; Human Machine Interface; 3D Aerial Image; Human Computer Interaction; 3D Visualization