Roukes' charge-measuring device measures about 20 millionths of a meter wide. Place about 50 them end to end, and they'd be about the width of a human hair. Some of the moving parts are as tiny as a few hundred billionths of a meter wide. It's just the beginning of the kinds of things we can do. Such devices include the sensors that activate airbags, and NASA is exploring the idea of a swarm of insect-size robots for future planetary exploration.
Nature is, so far, the only accomplished nanotechnologist.
Roukes points to the corkscrew tail of some bacteria. We'd love to know how to do that, but we don't. There are two approaches to trying to create machines of similar size. One is using a device called an atomic force microscope to literally pick up and place individual atoms, creating such objects as a tiny guitar . So far, however, these are just tiny art pieces that can't do anything.