"There are so many autonomous devices such as cell phones and laptops that have emerged in the last few years," said Assistant Professor Marin Soljacic from the Massachusetts Institute of Technology and one of the researchers behind the work.

"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?'."

The answer the team came up with was "resonance", a phenomenon that causes an object to vibrate when energy of a certain frequency is applied.