Nano nukes for micromachines?(research on miniature nuclear-powered batteries)

Computers grow smaller each year. Portions of food at fine restaurants likewise. Even the U.S. deficit is shrinking. So why not that die-hard of the industrial age, the machine?

We're not talking a little smaller, or even a lot smaller. As reported in the January/February Bulletin, researchers at Sandia National Laboratories have created tiny microelectro-mechanical systems, or MEMS, smaller than a grain of sand and capable of performing a variety of tasks. Some can spin wheels as small as .3 millimeters at 350,000 revolutions per minute. Others are equipped with mirrors or motors on the same scale.

One problem yet to be solved, however, is scaling down a suitable power supply. So far, no effective solution exists.

Not all MEM technology--also known as nanotechnology or micromechanics--needs power. The sensing devices used in automotive airbags, for example, just hang around waiting for something to happen mechanically. Other devices, however, require a jolt of power, and since even a hearing aid battery might be thousands of times larger than the machine itself, …