When you’re on the go and your smartphone battery is low, in the not-so-distant future you could charge it simply by plugging it into your shoe.

An innovative energy harvesting and storage technology developed by University of Wisconsin–Madison mechanical engineers could reduce our reliance on the batteries in our mobile devices, ensuring we have power for our devices no matter where we are.

The technology could enable a footwear-embedded energy harvester that captures energy produced by humans during walking and stores it for later use.

Power-generating shoes could be especially useful for the military, as soldiers currently carry heavy batteries to power their radios, GPS units and night-vision goggles in the field. The advance could provide a source of power to people in remote areas and developing countries that lack adequate electrical power grids.

“Human walking carries a lot of energy,” Krupenkin, a professor of mechanical engineering at UW–Madison said. “Theoretical estimates show that it can produce up to 10 watts per shoe, and that energy is just wasted as heat. A total of 20 watts from walking is not a small thing, especially compared to the power requirements of the majority of modern mobile devices.” professor added.