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.

In a paper published Nov. 16, 2015, in the journal Scientific Reports, Tom Krupenkin, a professor of mechanical engineering at UW–Madison, and J. Ashley Taylor, a senior scientist in UW–Madison’s Mechanical Engineering Department, described an energy-harvesting technology that’s particularly well suited for capturing the energy of human motion to power mobile electronic devices.