Nokia researchers are working on technology to harvest power from ambient electromagnetic radiation emitted from cell phone antennas, TV masts, WiFi transmitters, and other sources. The goal is to create cell phones that never needs recharging via the conventional power cord.
Ambient electromagnetic radiation--emitted from Wi-Fi transmitters, cell-phone antennas, TV masts, and other sources--could be converted into enough electrical current to keep a battery topped up, says Markku Rouvala, a researcher from the Nokia Research Centre, in Cambridge, U.K.
Rouvala says that his group is working towards a prototype that could harvest up to 50 milliwatts of power--enough to slowly recharge a phone that is switched off. He says current prototypes can harvest 3 to 5 milliwatts.