Little batteries pack big power

Combining nuclear- and electrical-engineering technologies, a trio of engineers hopes to make independently powered microelectromechanical systems (MEMS) about the size of a grain of sand.

Until now, researchers looking for such devices were limited by the comparatively large batteries needed to power them. But Engineering Physics Professors James Blanchard and Douglass Henderson and Electrical and Computer Engineering Assistant Professor Amit Lal have developed "nanobatteries" from minute amounts of coated radioactive material, similar to that in smoke detectors and pacemakers.

The batteries work by harnessing the material's natural radioactive decay, and could last for hundreds of years. The group's research is funded by a three-year, $970,000 Defense Advanced Research Projects Agency grant.