Scientists in Bedfordshire have developed a way of generating electricity as people walk.
The "Energy Harvester" is still in development but Cranfield University hopes it could help soldiers power vital equipment in the battlefield.
A prototype uses a computer to simulate the gait of a human walking, but small electronic gadgets could be placed on people's knees to power portable devices.
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 it's hoped future devices could generate more than 30 milliwatts.
Dr Michele Pozzi, from Cranfield University near Milton Keynes told ITV Anglia he believes the device will be small enough and powerful enough to power a range of equipment.
He says the main aim is reduce the number of heavy batteries soldiers have to carry into battle.
"Initially the project was funded by the Ministry of Defence. The idea is to find a reliable source of energy that can be used anywhere. Soldiers can carry up to 10kg of batteries to power their equipment. The "Energy Harvester" would reduce the need for that".
Dr Pozzi believes in the future the devices could also be used in sport.
"They could generate enough electricity to power a heart rate monitor, pedometer, GPS trackers or even MP3 players".
The product is in its infancy, but Dr Pozzi believes it can be manufactured at an affordable cost.
"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."