Nokia developing technology to charge phones from ambient radio waves?

Imagine never having to charge your cellphone ever again. Picture your phone scooping up ambient energy waves from cellphone antennas, Wi-Fi  transmitters or TV towers. It's not sci-fi, but is reality as the research team at Nokia is working on a way to keep your cellphone's battery topped off. A member of the Nokia Research Centre in Cambridge, Markku Rouvala, says his team is working on a way to collect up to 50 milliwatts of power from the electromagnetic waves which are converted into electrical signals. The 50 milliwatts of power would be enough to recharge a phone that has been turned off. Current prototypes can pick up about 3 to 5 milliwatts.

Intel's Joshua Smith, who co-developed a temperature and humidity sensor that uses power from a 1.0 megawatt television antenna 4.1 kilometers away, says that to obtain 50 milliwatts of power would require over 1,000 strong signals. Smith's sensor required only 60 microwatts. Another skeptic is Harry Ostaffe, head of mareting for Powercast, who said that, "To get 50 milliwatts seems like a lot".

Nokia's Rouvala says that this technology will probably be ready to be put in a handset in 3 or 4 years. He says that ultimately, the Finnish phone manufacturer plans on using the technology in conjunction with other energy saving faetures such as solar cells placed around the outside body of a handset.

source: Technology Review via EngadgetMobile