Sandia Creates First Diamond Micromachines.

They are not a suitable present for Valentine's Day, and they are too small to be a girl's best friend, but Sandia National Laboratories (Albuquerque, NM) has created what are believed to be the world's first diamond micromachines.

The machines are located at the Department of Energy's national security facility, and they are etched from a surface of amorphous diamond, the hardest material in the world after crystalline diamond, in a manner compatible with current silicon chip and surface micromachine manufacturing techniques. Diamond is of great interest to researchers because of its superior wear-resistant qualities, resistance to friction, and potential as a biocompatible material that could be used inside the human body for medical purposes without generating an allergic reaction.

Currently constructed is a diamond comb drive whose tiny interspaced teeth move forward as an electrical current reverses constantly between positive and negative, This is the first demonstration of a micro-motion drive using amorphous diamond. The point, according to researchers, is to create a layering technology useful in increasing the life span and performance of micromachines.

Researcher Tom Friedmann says, "Micromachines, for all their marvelously tiny size, are still machines. They're subject to wear, even if it's only at the micro level. Diamond is more wear-resistant than polysilicon. One estimate in the literature claims that diamond should last 10,000 times longer than polysilicon in wear applications. Our material is chemically benign and compatible with silicon. It could function as another station in the line in the creation of a basically silicon micromachine, but with a diamond layer for additional strength and durability. It could one day be used as a complete replacement for polysilicon."

Silicon MEMSs are already being used in a variety ...