Is your stride packed with vigor? Well, if you say ‘yup’, then the energy your each step releases can light up a bulb. SolePower goes a step further – it cumulates that energy and stores it as usable electrical power.

This system was designed by Matt Stanton and Hahna Alexander, sophomores at Carnegie Mellon. The shoe insoles are fitted with equivalent parts to ones, that a mechanically-powered, hand crank flashlight carry. At the start the young inventors built the power-producing inserts to illuminate an LED in the shoe. Worn by students walking to and from campus late at night – it lit up their path.

Each heel strike makes energy which transform into rotational energy to turn the tiny magnetic rotors – in turn trigger an electrical current to run through the coils of wire. Thereon the electricity is channeled along a cable into a lithium-ion polymer battery pack for storage. Small electronic gadgets are charged by way of a USB port installed on the external battery pack, and fastened onto shoelaces in a fabric holster.

The cumulative weight of the device including the external power pack comes to five ounces. Using the latest version, a 15-mile hike can charge a smartphone – and the team will soon come up with a design that will carry off the same in 5 miles and last about 100 million steps’ worth of wear and tear.

An identical power-generating, in-shoe concept developed in University of Wisconsin-Madison, stem from a technique dubbed reverse electrowetting. In this technique energy of metal droplets (in the soles) turn into an electrical current. When the conductive liquid drops are compressed or sheared by the electrode layer on top, voltage is produced.

The all-weather, detachable SolePower inserts can be shaped to fit any shoe. It’s a must-use by backpackers having very little space for extra juice packs. Or as backup for solar chargers on cloudy days and nights.