Phone company Nokia may be working on a mobile that charges itself using the energy created by its owner's natural movement.
According to a report in The Times newspaper the company has filed a patent covering the use of special crystals that generate an electric current when bent or compressed.
It's thought that Nokia researchers are working on a way to incorporate the crystals into phone designs so they can create a mobile that never needs to be plugged in.
If successful the technology could be transferred to all portable electrical devices, potentially doing away with batteries and chargers forever.
