Imagine of a cell phone that never needs charging! Wouldn't it be great if a cell phone gets charged when it is on stand-by? No need to worry about the battery of the phone even if you are away from home and without charger. Nokia says that its developing technology that could draw enough power from ambient radio waves to keep a cell-phone handset charged.

Ambient electromagnetic radiation, emitted from Wi-Fi transmitters, cell-phone antennas, TV antennas, and other sources could be converted into enough electrical current. The power harvested is small but it is almost enough to power a mobile in standby mode indefinitely without ever needing to plug it to the charger, according to Markku Rouvala, one of the researchers who developed the device at the Nokia Research Centre in Cambridge, UK.


Using the current techniques, 3-5 milliwatts of power can be harvested. Nokia is working towards a prototype that could harvest up to 50 milliwatts of power, enough to slowly recharge a phone that is switched off. The Nokia's device will work on the same principles as a crystal radio set or radio frequency identification (RFID) tag: by converting electromagnetic waves into an electrical signal. Rouvala further adds that, energy can be harvested even if you are getting only microwatts, provided your circuit is not using more power than it’s receiving.

To increase the amount of energy harvested, Nokia is working on harvesting frequencies of different ranges. Greater the range, greater the amount of electricity produced. To make this happen, waves should be harvested across the widest range possible.

However, total wireless charging won’t be possible unless it is used with other energy harvesting technologies, such as cell phones with solar back panels. It would be great to see such real “smartphones “in the upcoming years and if this occurs it would bring a great revolution in the electronics world.


Source : Technology review | Image credits : Gadget page