Nokia developing phone that recharges itself without mains electricity Prototype harvests radiowaves from TV, radio and other mobiles
http://www.guardian.co.uk/environment/2009/jun/10/nokia-mobile-phone quote <<...Nokia claims it is able to scavenge relatively large amounts of power — around a thousand times as much — from signals coming from miles away. Individually the energy available in each of these signals is miniscule. But by harvesting radiowaves across a wide range of frequencies it all adds up, said Rouvala. Such wireless transfer of energy was first demonstrated by Nikola Tesla in 1893, who was so taken with the idea he attempted to build an intercontinental transmission tower to send power wirelessly across the Atlantic. Nokia's device is somewhat less ambitious and is made possible thanks to a wide-band antenna and two very simple circuits. The antenna and the receiver circuit are designed to pick up a wide range of frequencies — from 500 megahertz to 10 gigahertz — and convert the electromagnetic waves into an electrical current, while the second circuit is designed to feed this current to the battery to recharge it.>> end quote Harry
