Knee Brace Generates Electricity From Walking

ktulus cry brings news of a device that can power portable gadgets, prosthetic joints, and other mobile appliances by harvesting energy generated by walking. Researchers are working on making the device — still a moderately cumbersome 3.5 pounds — smaller while maintaining its energy harvesting capacity. CNet has a write-up with more pictures and a diagram of the device. "In the mode in which the brace is only activated while the knee is braking, the subjects required less than one watt of extra metabolic power for each watt of electricity they generated. A typical hand-crank generator, for comparison, takes an average of 6.4 watts of metabolic power to generate one watt of electricity because of inefficiencies of muscles and generators. A lighter version would be helpful to hikers or soldiers who don't have easy access to electricity. And the scientists say similar mechanisms could be built into prosthetic knees other implantable devices such as pacemakers or neurotransmitters that today require a battery, and periodic surgery to replace that battery."

Comments

Well...

[vertinox]

Thats neat. But wouldn't it be more efficient for us slashdotters if it was put on our arms... Depending on which one is using the mouse... Or... Umm... The one not holding the lotion bottle?

Re:less than one watt for one watt?

[maxwell demon]

Care to explain how this statement, as it stands, does not conflict with the 2nd law of Thermodynamics?

That's simple: They violate the first law of thermodynamics, not the second one.

Re:Does it double its output ...

[mordenkhai]

Only if its Chocolate Rain.