Chemical etching technique could yield diamond based MEMS
1 min read
A new chemical etching technique developed by researchers at the National Institute of Standards and Technology (NIST) could one day lead to stronger, more durable Micro Electro Mechanical Systems (MEMS) made of diamond instead of silicon.
By combining their own observations with background gleaned from materials science, the NIST team found a way to create unique features in diamond, for the first time engineering it at the nanoscale. They believe the breakthrough could offer significant improvements in future consumer electronic devices.
"Diamond may be the ideal substance for MEMS devices," stated NIST's Craig McGray. "It can withstand extreme conditions, plus it's able to vibrate at the very high frequencies that new consumer electronics demand. But it's very hard, of course, and there hasn't been a way to engineer it very precisely at small scales. We think our method can accomplish that."
The method, according to McGray, involves taking advantage of the cubic shape of the diamond crystal, in a similar way jewelers do when cutting gemstones. Different planes running through the diamond are used as boundaries, to precisely stop the etching where desired.
In their initial experiments, the team created cavities ranging in width from 1 to 72 micrometers, each with smooth vertical sidewalls and a flat bottom.
"We'd like to figure out how to optimise control of this process next," noted McGray, "but some of the ways diamond behaved under the conditions we used were unexpected. We plan to explore some of these mysteries while we develop a prototype diamond MEMS device."
