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DECTRIS News
Hybrid-Pixel Technology in Electron Microscopy: Today and Tomorrow
Electron Microscopy (EM) is a fast-evolving field. Researchers and scientists are always developing new techniques and testing new approaches, while instrument manufacturers are releasing more automated and easier-to-use microscopes and integrating new technology to help yield better results.
One example of this evolution is the adoption of hybrid-pixel direct electron detectors by the community. We invited five leading electron microscopy experts to take a look at this change and share with us their outlooks on the development of this technology, as well as its impact on the field.
Hybrid-pixel electron detectors offer noise-free direct electron detection. Fast and radiation-hard, they deliver high-quality data and enable wider adoption of new electron microscopy techniques. Now, a few years after the introduction of dedicated electron detectors, we wanted to know how hybrid-pixel technology is perceived by the community and how its integration into modern electron microscopes affects the field. To gain perspectives from the areas of research, facility management, and instrument manufacturing, we invited five experts to discuss hybrid-pixel technology in electron microscopy--both today and tomorrow.
“When users have a hybrid-pixel detector on their spectrometer, they don’t bother with any other detector.”
Dr. Tracy Lovejoy, Nion Company: “I was an electron microscope user once; today, I represent an instrument manufacturer. My experience with the new technology is now completely different. On the one hand, as a user, I strived to get the best detector for my project. And I see the same behavior from the side of our customers: they are eager to try out this technology. Hybrid-pixel detectors are versatile and deliver outstanding performance. Before, users would consider switching between two cameras mounted on their instrument. Today, hybrid-pixel detectors seem to satisfy a wide range of requirements for most spectroscopy setups, effectively eliminating the need for an additional camera on the instrument.
“On the other hand, from the point of view of the instrument manufacturer, dealing with new technology is slightly different. Even though the integration of hybrid-pixel detectors was smooth, it still required some work on the mechanical aspect of the instrument and the user interface. But it was nothing we couldn’t overcome. I’m convinced that the development of hybrid-pixel detectors is not yet over, and we will see even faster detectors.”
“The detector is no longer a limiting factor.”
Dr. Cécile Hebért, EPFL/LSME: “It is difficult to find a perfect balance between state-of-the-art technology in a user facility and ease of use. If, to operate a different detector, one needs to run multiple software programs or reconfigure the microscope, no matter how good the result is, the experience as a whole will be negative. It is therefore crucial for detector manufacturers and instrument developers to communicate efficiently. If we can achieve a seamless integration of hybrid-pixel technology into the existing electron microscopy ecosystem, it carries a lot of potential for the field. For example, noise-free data could become a game-changer for techniques using machine learning.”
“In our research, every electron counts.”
Dr. Christopher Russo, MRC Laboratory of Molecular Biology (LMB): “Our research depends on the detector’s efficiency. We spent a lot of time trying to understand the optimal energy for imaging of biological specimens. We realized that the optimal energy is thickness-dependent, and, since the majority of our specimens are of a similar thickness, the optimal energy would be around 100 keV. That came as a big surprise to the cryoEM community. A lot of effort was put into the development of instruments designed for higher energies, and our discovery contradicts that trend.
“We went back to the drawing board, trying to imagine an instrument that could not only be cheaper, but also possibly be even better in solving structures of biological specimens. That is where hybrid-pixel detectors caught our attention; they allowed us to get the maximum information out of each electron. The first experimental results convinced us that we were on the right path, and that hybrid-pixel detectors are the right tools for us.”
One of the first cryoEM images that were obtained with a SINGLA hybrid-pixel detector at 80 keV. MRC Laboratory of Molecular Biology, © 2021. All rights reserved.
“What counts is the quality of the reconstructed image. To reach that quality, we need a fast detector with 95% DQE.”
Dr. Greg McMullan, MRC Laboratory of Molecular Biology (LMB): “What researchers and users want is to make the most of their time with a microscope. In our experience, fast detectors with a high DQE are the best option for Life Science research. A high DQE directly translates to the quality of the reconstructed image, as it allows for better positioning and orientation with lower doses. The detector’s speed reduces the acquisition time. Working with a radiation-hard hybrid-pixel detector is also convenient: if you lose your beam, it is not a problem for the detector to go from identifying individual electrons to being exposed to 10 nano-Amps and back.”
“Where we are now is good; where we are going to be is even better.”
Dr. Richard Henderson, MRC Laboratory of Molecular Biology (LMB): “There is no end to what you can do with a detector. Once you’ve reached 100% DQE (0), it would seem that there is not much else you can do better, but you can try to optimize it all the way out to the Nyquist frequency. Hybrid-pixel detectors could reach that. We are very keen to see this type of detectors be developed further: to see even faster detectors, larger detectors, easier-to-operate detectors.”
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