With sizes typically measured in micrometers, Micro-electromechanical systems (MEMS) devices are already being used in applications such as super-accurate sensors, energy-harvesting devices, and electronic signal amplifiers. Given how difficult it would be to replace such systems' moving parts as they wear out, it would be ideal if those parts could be made from as hard a material as possible. Well, while most MEMS are presently made chiefly of silicon, researchers from the National Institute of Standards and Technology (NIST) are now on their way to making them from diamonds.
While diamond is one of the hardest substances in the world, it so far hasn't been possible to carve at the nanoscale. The NIST team, however, has succeeded in doing so, using a chemical etching technique.
The process involves taking advantage of the cubic shape of the diamond crystal, much as jewelers do when cutting gemstones. Different planes running through the diamond are used as boundaries, to precisely stop the etching where desired. So far, the researchers have succeeded in making smooth-walled, smooth-bottomed cavities ranging from 1 to 72 micrometers across, within diamond samples.
The NIST researchers now plan on learning how to better control the process, and creating a prototype diamond MEMS device.