High-Dimensional Compressive Scanning Transmission Electron Microscopy

While modern transmission electron microscopy (TEM) is an incredibly powerful tool for nanoscience and biology, in terms of information theory it is extremely inefficient; the great majority of the information acquired in TEM consists of noise and redundant and irrelevant information. The effort to acquire this information costs time and can tax the bandwidth of even the best modern electronics, all the while bombarding the sample with destructive radiation and still missing the inherently high-speed fundamental behavior of the bio- and nano-systems under study. How the Problem is Being Addressed: Compressive sensing, a fast-growing field that applies data compression theory to the acquisition of data rather than just the storage and transmission of data, can solve the problem by operating the hardware such that the redundant information is never acquired in the first place. This project uses IDES' unique programmable high-speed deflector technology to implement data compression in the time domain, effectively improving continuous-acquisition camera frame rates by factors of 100 or more. Combining this with high-dimensional acquisition modes including spectrum imaging, scanning diffraction, and time resolution should make it possible to acquire vast information-rich high-resolution data sets even on radiation-sensitive materials. Phase I/II Accomplishments: After an extensive theoretical/computational Phase I study to develop algorithms and identify the best path forward, Phase II saw the development and first commercial introduction of a compressive TEM video product capable of 100-fold frame rate improvements. Two beta units are already functioning in customers' facilities, and journal articles are in preparation. A post- beta system is slated for release at the end of Phase II. Phase IIA Goals: Complete the development of data analysis algorithms and user-friendly software, and introduce a pre-sample beam blanker that coordinates with the compressive video system for precise timing and dose control. Commercial Applications and Other Benefits: Compressive sensing greatly widens information bottlenecks and enhances throughput, making feasible many studies that in the past would have required far too much time and electron dose. Especially given the importance of emerging bio/nano hybrid technologies for advanced energy applications, these past limitations are a serious problem across a vast range of applications.