Nokia is developing a mobile phone that would utilise the ambient radio waves to recharge itself.

The new technology would work on the same principles as the Radio frequency Identification (RFID) tags and would convert ambient electromagnetic waves into electrical signals.

The mobile phone will use the ambient electromagnetic radiation, emitted from Wi-Fi transmitters, cell-phone antennas, TV masts and other sources.

Markku Rouvala, of Nokia Research Centre in Cambridge, UK, said 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.

Even if you are only getting microwatts, you can still harvest energy, provided your circuit is not using more power than it’s receiving, Rouvala added.

The company is also expected to use other energy-harvesting technologies, such as solar cells embedded into the handset casing.