Revolutionary spinner

2019-03-08 08:08:17

By Duncan Graham-Rowe NANOTECHNOLOGY researchers have spun a tiny device at phenomenally high speeds. The researchers at Sandia National Laboratories in Albuquerque, New Mexico, were demonstrating the size of a microscopic gear wheel when they found that the ultra-low friction component—part of the world’s smallest combination lock—can spin at an undreamt of 350 000 revolutions per minute. To demonstrate the size of their “nano-lock”—a device that might one day keep hackers out of computer networks—the researchers placed a spider mite on top of a 0.3 millimetre diameter gear wheel. “It looked like an elephant by comparison,” explained Larry Dalton, an engineering manager at Sandia. Out of curiosity they then started to spin the device with an electrostatic motor to see how fast it could go, giving the mite the ride of its life. At 2000 rpm they let the somewhat disoriented mite off, and at 350 000 rpm they realised they were on to something. They calculated that if they designed a gear specifically for speed they could go as fast as 10 million rpm, which could make such devices ideal for use as high-speed switches in an optical computer. In the macro world, the best machine tools can achieve speeds of around 20 000 rpm—any faster and friction becomes insurmountable. But in the microscopic world, friction and inertia are less of a problem owing to the decreased masses involved,