No more gadget chargers

Electronic gadgets could soon automatically charge up when their owners wander into their home or office - without the need for cumbersome cables or chargers.

Physicists at MIT have devised a system that could supply power to devices such as laptops, mobiles and MP3 players without wiring up to the mains.

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Marin Soljacic, assistant professor of physics at MIT, told silicon.com the device would work in a similar way to wi-fi, with a plug-in device in the home or office providing a signal to recharge all types of gadgets.

Any device in need of a power-up would need to be fitted with a card, similar to a wi-fi card in a laptop, to receive the signal and start charging, Soljacic added.

When any device fitted with a 'recharge card' came within range of the emitter (around three to five metres), it would automatically replenish its energy stores.

The proposed system uses magnetic fields that shouldn't affect humans.

The team has not tested a physical system yet but computer models and mathematics suggest it will work.

Soljacic said experiments to develop the physical device are already underway and are expected to be completed within one year.