Inventors of the tiniest machines have tapped various power sources for their devices: electricity, light, even DNA. Now, Amit Lal of Cornell University and his colleagues are fueling a tiny oscillating cantilever with nuclear energy.
Because a single load of nuclear fuel can last a half-century or more, the devices might serve as microsensors on long, lonely jobs such as monitoring stockpiled missiles, Lal says. The researchers are now adapting the cantilever to drive a rotary motor, he adds.
The device, which works only in a vacuum, gets power from nuclear decay within a film of radioactive nickel-63. As the nickel decays, ejected electr