A High Performance Direct Electron Imager

The development of Transmission Electron Microscopes (TEM's) has made tremendous progress in the last few years and these instruments are now routinely used in laboratories across the world to obtain structural data from many materials at resolutions beyond 100pm. However the detectors that are essential for digital recording of images, diffraction patterns and spectra are still based on old technology which limits the performance of these instruments (the detector gap ). The basic problem lies in the construction and operation of detectors which are based on Charge Coupled Devices (CCD's) similar to those used for optical imaging. CCD's are damaged if directly exposed to the electron beam and must be coupled to a scintillator which converts the beam electrons into photons. These photons are then recorded by the CCD. Previous research under an EPSRC funded project has developed an entirely new type of sensor that can be directly exposed to medium energy electrons as an alternative to indirect detection. This sensor has been shown to have a far greater sensitivity than indirectly coupled CCDs (it is capable of detecting single electrons) and has far higher resolution. In addition it can be operated in a counting mode providing an infinite dynamic range. These significantly improved characteristics will enhance the output from TEM's by providing less noisy digital images and spectra enabling materials to be studied with less radiation exposure. This is vitally important when the TEM is used to study many modern materials, such as semiconductors, catalysts and carbon based nanostructures which are often damaged in the electron beam. It will also be critical for imaging biological materials which are extremely electron sensitive and where the enhanced sensitivity will be of considerable benefit. We now intend to develop the commercial potential of this novel the 1D sensor through the construction of a functional 2D imaging as a commercial prototype. This will require fabrication of a large array 2D sensor using our existing technology, the integration of suitable readout electronics and the design and construction of a suitable mechanical / vacuum interface to form a prototype imaging system. We will then use this to demonstrate to investors the clear advantages of this technology over existing detectors in a range of application examples from both biology and materials science. All of these steps have been demonstrated to be technically feasible within the orginal project and are essential steps in realising the commercial potential of the sensor.

The primary beneficiaries of the proposed research are industrial organisations who will be able to take up licensing agreements as defined in the commercial case for support. These organisations include TEM column manufacturers and OEM suppliers of ancillary equipment fitted to TEMs. The wider group of beneficiaries includes all end users of TEM based instrumentation who will be able to take advantage of the substantially improved detection characteristics of a new type of imaging system. These include research groups in academia, industry, national standards agencies and the health care sector in the Uk and abroad who have been identified as users of TEM instruments. All of these will benefit through the availability of higher quality digital data that will in the future influence the quality and competitiveness of the UK's research output in this field. As exemplars the UK has leading electron microscopy laboratories working in the structural determination of cellular structures with direct relevance to clinical research and has the highest concentration of aberration corrected TEM instruments in Europe. In the longer term the sucessful demonsration of a functioning imaging system will add value through more profitable commercialisation in which the performance metrics and costs of manufacture are clearly understood and will inform the applicants and commercial partners as to the value of an extended range of detectors. The staff working on this project will benefit through exposure to a multidisciplinary research environment and through commercial interactions both of which will diversify and enhance their subsequent employment opportunities. In order to realize maximum benefit to the beneficiaries the proposed research has in place clear plans for collaboration and exploitation backed by the experience and track record of the internationally recognised EIA group who will undertake the research. As a key component of the proposed research there is in place extensive IP protection of the core technology through a core patent filed in the EU and the USA. To initiate suitable collaborations with potential future industrial partners we have identified a number of initial beneficiaries with whom we have non disclosure agreements and commercial options in place negotiated on behalf of the investigators by Isis Innovation. To ensure effective and widespread communication of the output from the proposed research we propose to arrange demonstrations of the prototype system for commercial evaluation and to continue to disseminate the research data through peer reviewed publication and international conference presentations.