CityU 1st in electron microscope research
By : Michael Gibb
Electron microscopes (EMs) are huge because they can be so small, and CityU is pioneering their development.
EMs are highly sought after because they produce much clearer images than light microscopes and provide measurements and analysis at the micro-nano and even the atomic scale.
In medicine, they can be used to observe cells and tissue; in materials science, to observe microstructures and surface morphology, which is useful for microcircuits and semiconductors; in food science, to inspect particles and crystals in food or analyse the composition and structure of food.
Clear and precise
In fact, electron microscopes are among the most popular instruments for material characterisation due to their outstanding resolution and ability to detect various phenomena. That’s why news earlier this year that CityU scientists led by Professor Chen Fu-rong of the Department of Materials Science and Engineering are pioneering advanced technology for the next-generation self-designed and manufactured EMs generated so much excitement.
(From left) Professor Chan Chi-hou, Professor Chen Fu-rong and Dr Hsueh Yu-chun. With support from the Futian District Government, the CityU team is the only university-based research group to have produced several high-end EMs, explains Professor Chen, concurrently Associate Vice-President (Mainland Collabration), Director of the Time-Resolved Aberration-Corrected Environmental (TRACE) Centre and Director of the Shenzhen Futian Research Institute at CityU.
The problem in EM development has been both radiation damage and the static view of the sample, which hinders studying small molecule and electron beam-sensitive materials. Furthermore, EM size limits their application in space-expensive environments, such as space shuttles and deep sea and deep earth research ships and devices.
To overcome these limitations, the CityU research team designed pulsed electron sources and a fast camera that can be used with a desktop EM. By equipping the fast camera with a deflector, the speed of imaging is not limited to the readout time. This is the first time such a concept can be verified on a desktop EM system. The team also designed an aberration corrector, which can further improve imaging resolution.
The smaller, the better
According to the CityU team, the miniaturisation of high-end instruments such as EMs is an inevitable trend. The problem is that conventional EMs are accessible in laboratories only and require trained operators, which limits their deployment. But miniaturisation will enable usage in extreme environments such as space stations, for example, since the instruments will be more portable and hence more user-friendly.
“The miniaturisation of a device typically results in lower production costs and increased accessibility. Consider the evolution of computers as an example: Initially, computers were developed to perform complex calculations for military decoding and space missions. However, with the advent of PCs, demand now far exceeds that of supercomputers. Demand for even smaller devices, such as mobile phones and tablets, continues to grow,” explains Dr Hsueh Yu-chun, Research Fellow at TRACE.
Why has CityU been so successful in this area of research? The design and manufacturing of EM is an excellent example of interdisciplinary research, requiring experts in materials science, mechanical engineering, electrical engineering, and applied physics.
“The marketing and intelligence rights have been dominated by companies in the US, Europe and Japan in the last decades, but CityU has a group with senior scientists in the field of electron microscopy who know the trend in development and how to design and fulfil current needs,” says Dr Hsueh.
“Also, with support from CityU and the government, our team can overcome scientific and engineering problems, and we are eager to enter the niche market with our products equipped with unique functions and compete with foreign companies,” he adds.