January 2001

Nanotech Goes to Work

Continued from page 3

By David Rotman

Tiny Tunes

the reliance on afm tips and cantilevers illustrates a decidedly mechanical bent in much of today's nanotech research. Indeed, the strategy of using small silicon-based machines called MEMS (microelectromechanical systems) to manipulate nano devices is turning out to be an especially promising area. These micromachines are hundreds or thousands of times bigger than the nanoscale and are commercially used in everything from automobile air bags to switches in optical networks. But in the hands of skilled researchers, MEMS can offer a valuable way to control nano action.

In turn, the incorporation of nanoscale structures can greatly increase the utility of existing MEMS technology. "There are a number of situations with devices a few tens or even thousands of micrometers in size where one critical dimension needs to be smaller. Right at the heart of the device you may need a nanoscale feature," says Michael Roukes, a physicist at the California Institute of Technology. Nanomachines are particularly useful in responding to "very feeble forces," says Roukes, who has recently fabricated devices such as a nano resonator, which vibrates like the strings on a tiny guitar. Incorporating these nano devices into MEMS could, for example, yield signal processors that consume minuscule amounts of power.