Gadgets could run on knee power
Wearable electronic gadgets could in future be powered by people's knees, a study has shown.
Scientists have tested an "energy harvester" electricity generator designed to be strapped to the knee.
Walking motion causes plectrum-like tabs within the device to "pluck" energy generating arms, causing vibrations that produce electrical current.
So far researchers have only been able to generate a tiny two milliwatts of power, but improvements are expected to yield more than 30 milliwatts.
Foot-slogging soldiers may find the knee generator useful since they often have to carry up to 10 kilos of power equipment, say the scientists.
The device was tested on a knee motion simulator that reproduced the gait of a walking human.
Dr Michael Pozzi, from Cranfield University in Bedfordshire, whose work appears in the journal Smart Materials and Structures, said: "There is an on-going project looking at manufacturing a more compact and truly wearable harvester.
"At the moment we are using precise but cost-effective manufacturing techniques for the plectra and casing and anticipate that remaining parts will be moulded industrially, slashing the cost.
"I'd put a cost tag of less than £10 for each harvester on a large-scale production."