Put simply, microengineering is the design and fabrication of devices and systems that have at least one feature that is on the micron scale, or one millionth of a metre. This begs the question;
isn’t this standard mechanical engineering, just shrunk down to a smaller scale?
There are certainly common features between the two fields, but there is a limit to how small classic machining methods, such as milling, can go. This is all due to how objects and forces scale.
To give a sense of perspective, consider a human hair. It is about 50-100 microns in diameter. Due to its small size, the hair is highly flexible and would not be a good cutting tool, so we have difficulty milling at this scale. This is the problem with scaling down classic fabrication techniques.
Microengineering therefore uses non-conventional ‘tools’ such as plasmas, charged particles, chemicals and lasers to create a huge array of complex small structures that are used in all areas of life; from sensors in cars to ink-jet printers. As these small structures can be integrated with electronics on a single chip, they can be used to perform tasks that are simply impossible otherwise. These technologies allow scientists to probe the behaviour of cells1 and to detect other planets2. The field of microengineering is a quickly evolving one that is revolutionising all areas of science and our everyday lives.
1 Hai, A. et al. (2010), Long-term, multisite, parallel, in-cell recording and stimulations by an array of extracellular microelectrodes, J. Neurophysiol. Vol. 104, pp. 559-568
2 Ford, H.C. et al. (2003), Requirements for an optical 8-m space telescope with a MEMs deformable mirror to detect Earth-like planets around nearby stars, Proc. SPIE 4854, Future EUV/UV and Visible Space Astrophysics Missions and Instrumentation, 554