An Intel boffin has come up with a way to harvest electricity from the airwaves, and he hopes the technique could be used to power mobile phones or small gadgets sometime in the future.

By using a TV antenna pointed at a massive TV tower, Intel researcher Joshua Smith and student Alanson Sample managed to power a small LED thermometer. It's a good start, but nowhere near enough for any truly practical use. Obviously there are tons of digital and analogue signals at various frequencies, traveling through the air and even our own bodies, but making any use of what basically amounts to radio pollution isn't easy.

"That's the thing with these broadcast mechanisms - if you don't collect the power and do something with it, that energy's just going to, you know, heat up the grass or something," says Smith. "There's nothing else that could happen with it."

Smith hopes that the technology could be used to provide mobile devices with extra power sometime in the future, allowing them to remain on standby indefinitely. It will probably never produce enough power to forgo chargers and batteries, but every little helps.

One of the more interesting ways of using the technology would be to create wireless keyboards, mice and gamepads, and Smith believes that in a couple of years we could see a truly wireless mouse or Wii controller, powered by Oprah.

Nokia is also trying to harvest power emitted by cell towers, as well as TV towers and other transmitters, and MIT used a similar approach to light a light bulb in 2006.

More here.