Adaptive optics or the ability to arbitrarily control the shape of optical lenses finds widespread use in all fields op modern optical technology and research. In this project we investigated the possibility to provide a similar functionality for electron optics, where light waves are replaced by waves of accelerated electrons. This is of high interest in the field of electron microscopy where such waves are used to image materials up to the individual atoms that make up their structure.
We created a prototype consisting of an add-on for an existing transmission electron microscope instrument that provides an array of up to 48 programmable elements to control the phase of the electron wave. The electron optical element is manufactured with a lithographic process on a silicon chip and different alternative organisations of the 48 elements were designed and tested. The chip is placed on a dedicated carrier inside the vacuum of the electron microscope and is mounted on a custom designed holder that brings all contacts to the outside of the microscope. An electronic controller was designed to provide all 48 elements with a precise electrostatic potential that can be operated from a dedicated user interface.
Several technological challenges were encountered and solved during the course of the project and the result is a prototype with almost double the amount of pixels as set out at the start of the project. The prototype uses only technologies that can be replicated on a larger scale, providing an attractive route for bringing it to market. Contacts with several industrial partners were made in order to inform them about the potential of this new technology and to pave the way for future license deals. Due to challenges met in the construction of the prototype, demonstration experiments had to be shifted in time resulting in potential license takers to postpone their decision.
Preliminary contacts with scientific partners and interested industrial partners during multiple international conferences and business meetings has been extremely positive. Besides TEM instruments, a clear indication arose that also scanning electron micropes (SEM, a smaller and more affordable variant of an electron microscope) could strongly profit from this technology potential providing the world with a much smaller and much more affordable electron microscope while opening a whole new level of performance.
As microscopy is the key driver in gaining insight in the nano and atomic scale buildup of materials and life, our disruptive technology could have far reaching consequences in nearly any domain of our everyday lives. To give only one specific example: adaptive electron microscopy could help to bridge the missing gap from nanometer to angstrom scale in revealing the buildup of cell membranes or viruses to better understand their function and to develop more specific drugs to fight disease.
