Despite its name, this atomic battery couldn't exactly power the Batmobile's turbines. But it would be perfect if Bruce Wayne ever wanted to build a Bat-nanobot.

Invented by a team of Cornell University researchers, is made of a tiny strip of copper (1mm wide, 2cm long, and a razor thin 60 micrometers thick) and a thin film of the radioactive isotope silver-63. As the isotope decays it emits non-hazardous electrons, or as nuclear scientists like to call them, "beta particles." As the electrons are soaked up by the copper strip, it acquires a negative electric charge, while the loss of electrons gives the isotope a postive charge. And that means electrostatic attraction.

When the electrostatic pull is strong enough, the copper strip dips down towards the isotope. When they get close enough together, a electric spark jumps from the copper to the isotope and their charges are equalized again. The copper strip snaps back up, and the whole process begins again. Rather like one of those novelty toy birds that dips its beak over and over into a glass of water.

But since many radioactive materials take a very long time to decay, the battery could still be running decades after you'd sold that toy bird at a garage sale. Silver-63 for example has a half-life of about 100 years, so it should be able to power the battery for about 50 years. Other isotopes have different half-lives and radioactive strength, so a wide variety of battery types could be made.

The flexing copper strip itself could be attached to a tiny wheel or other mechanism for transferring energy. Proposed uses include powering tiny robots, or running sensors that need to operate for long periods without maintenance.

http://www.news.cornell.edu/releases/Oct02/cantilever.ws.html

-- Robert Myers