Feeds

Thigh-drive phone charger put through its paces

Let your legs help your fingers do the walking

The essential guide to IT transformation

North American boffins have produced a knee brace which can generate several watts of power as the wearer's leg flexes while walking. The inventors believe the device could be useful for powering medical equipment - and even mobile phones.

In a paper for the boffinry journal Science, the researchers reveal their device's test results. The knee generator works on the same principle as the regenerative brakes used in battery-driven cars. It can clutch in and out, so creating resistance only during selected periods of the leg's motion.

The leg-powered generator in testing

Still not enough power to get this treadmill moving.

If the gizmo engages itself only during the "braking" period, when the knee is bending to absorb the body's weight after a footfall - thus actually helping the leg somewhat with its task - it puts out an average of 5W when fitted to a man walking slowly.

This isn't enough for most applications, of course - it can't power lights, vehicles or heating. But it compares well with the output levels offered by portable batteries. The knee brace could power ten mobile phones, or charge them up. And unlike ordinary hand-cranked or pedal generators, it doesn't require any attention from the operator - though he or she does have to keep walking.

According to biomedics and engineering prof Arthur Kuo of the University of Michigan, one of the inventors, the leg generator doesn't require a significant level of effort from the user - though it's still too cumbersome.

"We've demonstrated proof of concept," Kuo said.

"The prototype device is bulky and heavy, and it does affect the wearer just to carry. But the energy generation part itself has very little effect on the wearer, whether it is turned on or not. We hope to improve the device so that it is easier to carry, and to retain the energy-harvesting capabilities."

Kuo sees systems of this sort being used by soldiers, to charge the increasing load of electronics they carry. The idea could also power implanted medical gear like pacemakers or neurotransmitters.

One likely consumer app might be for hikers or other outdoorsy types wishing to keep their gadgets charged up. (Trade names: Walkman, ThighPod, You'll-never-walk-alone-Phone. Etc.) But it's hard to imagine regenerative knee braces being a big hit among those with frequent access to grid power. ®

Gartner critical capabilities for enterprise endpoint backup

More from The Register

next story
Boffins attempt to prove the UNIVERSE IS JUST A HOLOGRAM
Is this the real life? Is this just fantasy?
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
China building SUPERSONIC SUBMARINE that travels in a BUBBLE
Shanghai to San Fran in two hours would be a trick, though
SpaceX prototype rocket EXPLODES over Texas. 'Tricky' biz, says Elon Musk
No injuries or near injuries. Flight stayed in designated area
Galileo, Galileo! Galileo, Galileo! Galileo fit to go. Magnifico
I'm just a poor boy, nobody loves me. But at least I can find my way with ESA GPS by 2017
Astronomers scramble for obs on new comet
Amateur gets fifth confirmed discovery
prev story

Whitepapers

Best practices for enterprise data
Discussing how technology providers have innovated in order to solve new challenges, creating a new framework for enterprise data.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Advanced data protection for your virtualized environments
Find a natural fit for optimizing protection for the often resource-constrained data protection process found in virtual environments.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?