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Bio-mechanical electricity - 13W per knee. Answered

A stroll around the park may soon be enough to charge the raft of batteries needed in today's power-hungry gadgets.

US and Canadian scientists have built a novel device that effortlessly harvests energy from human movements.

The adapted knee brace, outlined in the journal Science, can generate enough energy to power a mobile phone for 30 minutes from one minute of walking.

A slow walk can generate an average of 5W of electricity, but they have models that will produce 13W - enough power for a one-minute stroll to provide half an hour of talk-time.

The prototype makes you sound like an extra in Terminator, but the inventors are predicting saleable products within 18 months, probably powering (in the first instance) modern prosthetic limbs.

Soldiers may also benefit from wearing the knee brace to power the multitude of devices they now carry ,such as night vision goggles and GPS.

"They treat batteries like they treat food and water - they are so essential to what they do," he said.

Link to BBC article
Link to BBC Video
Link to Science Magazine article

This whole idea seems like a "Good Thing" to me - even without the computer-control, I don't see why a pedestrian or jogger couldn't wear a pair of generators similar to those in wind-up torches, charging phone and PDA as you stroll around doing the shopping or jogging across the park. Get them with a Nike or Motorola logo, and we'd see hundreds of people wearing batman-style utility belts, stacked with all the gadgets the modern human "needs". It could really help wearable computing take off as well.


The only problem I can see is the extra stress it exerts on your body. Maybe for walking butt this would kill a jogger.

The idea is that it wouldn't.

The generator free-wheels for that part of the stride when you are putting effort into bending and accelerating your leg, then kick in for the part of the stride when you are straightening your leg and slowing it down before it hits the joint too hard.

It could actually prevent joint damage.

Just saying that I've seen these a long time ago and none of them have gone commercial yet.

bout time someone started thinking that humans could generate electricty :]

Seeing the way this works, this looks like a way to further enhance one's exercise. This could be just as useful, it appears, on a treadmill, etc.

Hamstring? Who needs that anyway :p