Feeds

Thigh-drive phone charger put through its paces

Let your legs help your fingers do the walking

Intelligent flash storage arrays

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. ®

Remote control for virtualized desktops

More from The Register

next story
Renewable energy 'simply WON'T WORK': Top Google engineers
Windmills, solar, tidal - all a 'false hope', say Stanford PhDs
Rosetta probot drilling DENIED: Philae has its 'LEG in the AIR'
NOT best position for scientific fulfillment
FORGET the CLIMATE: FATTIES are a MUCH BIGGER problem - study
Fat guy? Drink or smoke? You're worse than a TERRORIST
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
HUMAN DNA 'will be FOUND ON MOON' – rocking boffin Brian Cox
Crowdfund plan to stimulate Blighty's space programme
Post-pub nosh neckfiller: The MIGHTY Scotch egg
Off to the boozer? This delicacy might help mitigate the effects
I'M SO SORRY, sobs Rosetta Brit boffin in 'sexist' sexy shirt storm
'He is just being himself' says proud mum of larger-than-life physicist
NASA launches new climate model at SC14
75 days of supercomputing later ...
LIFE, JIM? Comet probot lander found 'ORGANICS' on far-off iceball
That's it for God, then – if Comet 67P has got complex molecules
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Internet Security Threat Report 2014
An overview and analysis of the year in global threat activity: identify, analyze, and provide commentary on emerging trends in the dynamic threat landscape.
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.