Walk to Charge your Cell Phone

Charge your Cell Phones by wearing these special shoes, developed by Tom Krupenkin and J. Ashley Taylor at the University of Wisconsin Madison. Tom Krupenkin who is a professor of mechanical engineering, describes in an article in Nature Communications paper about the energy-harvesting technology known as “reverse electro-wetting” a phenomenon discovered by the two researchers. Electro-wetting is when “the shape of a liquid droplet sitting on a liquid-repelling surface is charged by applying voltage to the surface. Krupenkin and Taylor’s technology, however, reverses this principle.

Both the scientists now aim to commercialize their technology at the company they have recently founded – InStep NanoPower. Krupenkin and Taylor expect the energy harvester to be ready in two years. They developed this technology with a grant from the National Science Foundation.

How it Works:

The mechanical energy is converted to electrical energy by using a micro-fluid based device, consisting of thousands of liquid micro-droplets interacting with a nano-structured substrate. Placed in a shoe, the device captures the energy of moving micro droplets and converts it into electrical current.

Usage:

There is enough power, according to the researchers, to charge a standard mobile phone or laptop. Getting the energy from the device to the handset presents another challenge. One way is to plug a USB cable into the shoe – probably not the most practical option.

There are a lot of places where this kind of power would be useful. The military could put it in boots and cut way back on the number of batteries a typical soldier has to carry. Right now they have to walk around with up to 20 pounds worth to power various electronic devices such as night vision goggles, laptops and GPS units.

If nothing else, this method of powering phones might end up encouraging more people to exercise. And think of the possibilities if you run marathons.

Another solution would be to use the power-excavating shoe as an intermediary between cell phone towers and your phone, like a long-distance radio. As searching for a signal is a huge drain on a phone’s power, Krupenkin said this method is a huge energy saver and could make your phone’s battery last as much as 10 times longer.