US researchers have outlined a relatively simple system that could deliver power to devices such as laptop computers or MP3 players wirelessly.

The concept exploits century-old physics and could work over distances of many metres, the researchers said.

"We started thinking, 'it would be really convenient if you didn't have to recharge these things'.

"And because we're physicists we asked, 'what kind of physical phenomenon can we use to do this wireless energy transfer?'."

.:}Arctic Fox{:.