NEWS: Physics promises wireless power

John Navas · 2006-11-15T06:35:50+00:00

: The tangle of cables and plugs needed to recharge today's electronic gadgets could soon be a thing of the past. 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. Although the team had not built and tested a system, computer models and mathematics suggest it would work. "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?'." Energy trap 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. "When you have two resonant objects of the same frequency they tend to couple very strongly," Professor Soljacic told the BBC News website. Resonance can be seen in musical instruments for example. "When you play a tune on one, then another instrument with the same acoustic resonance will pick up that tune, it will visibly vibrate," he said. Instead of using acoustic vibrations, the team's system exploits the resonance of electromagnetic waves. Electromagnetic radiation includes radio waves, infrared and x-rays. Typically, systems that use electromagnetic radiation, such as radio antennas, are not suitable for the efficient transfer of energy because they scatter energy in all directions, wasting large amounts of it into free space. To overcome this problem, the team investigated a...

Nov 15, 2006 80 Replies

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SMS 19 years ago

True, but I'd probably buy a very low power laptop if I was going to be carrying the panels around. You can get laptops that draw only 10-12 watts, at least in Japan. Smaller screens, and lower performance processors, but adequate for most routine tasks.

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