Ultra-High Frame-Rate Pixelated Direct Electron STEM Detector

Electron microscopy (EM) is the primary method to image biological cellular ultrastructure, though it has not been possible to label and distinguish different kinds of molecules in a single image- This serious limitation has recently been overcome with the technique of selective lanthanide ion tagging and electron energy-loss filtered imaging yielding multi-color EM that is analogous to multi-color fluorescence microscopy but at up to 100x the magnification- The technique is laborious, relies on expensive equipment, and is quite inefficient since far less than 1% of incident electrons are used to create the elemental maps-An improved technique for multi-color EM will enable the routine imaging of multiple subcellular components, distinguished by individual colors, at the same time- Development of an entirely new direct electron detection sensor and camera system to enable image-wise collection of the entire scattered transmitted beam for each scan point in the Scanning Transmission Electron Microscope (STEM) will enable efficient multi-color EM- The proposed method will use the elastically scattered electrons, (scattering varies as function of Z4/3) to obtain “Z-contrast” and capture nearly 10 – 30% of the incident electrons to get elemental discrimination in the STEM, providing a much higher throughput and more broadly accessible alternative to Electron Energy Loss Imaging- The system, to be useful over large fields of view, will operate at scan rates 2 orders of magnitude faster than current pixelated systems-