Ever been outside and like really needed to charge your phone. No outlet in sight and no one has a portable charger.. Not a problem anymore. A pair of University of Wisconsin-Madison engineers have developed a new invention that allows you to charge your phone by plugging it into your shoe. That's right, your shoe. Tom Krupenkin, a professor of mechanical engineering, and J. Ashley Taylor, a senior scientist, reported in November 2015 that a new technology that's"well-suited" for harvesting energy from human motion to power mobile electronics. Krupenkin stated that "human walking carries a lot of energy," and "theoretical estimates show that it can produce up to 10 watts per shoe, and that energy is just wasted as heat." Krupenkin and Taylor are looking for industry partners to help them commercialize their footwear through their startup company, InStep NanoPower.