Two researchers from the University of Wisconsin have invented a way to recharge a battery without the need for a wall socket. Instead, you plug your device into your shoe and just start walking.

According to Geek.com, "Electrical power harvesting from mechanical energy is not a new concept, and relies on reusing the energy generated from another process, in this case walking. The problem comes from how much energy can be converted using this syetms using existing methods which have only produced minimal power levels until now. However, the research pair's system is capable of generating up to watts rather than the more typical milliwatts of power-enough for a decent charge. The system reverses the process of electrowetting and uses a new microfluidic device that forces conductive liquid microdroplets through a nanostructured substrate. In its simplest terms, the movement of this liquid through the system creates a flow of electricity ready to be harnessed by whatever you plug in."

However there is one problem, how to connect it to the shoe so you can walk with it and not trip over the wire. Also, this could be an airport security nightmare.

Then there is the possibility of something blowing up...I for one would rather keep electronics away from my feet while walking.

There is also the idea of using Nano technology that can harvest energy by converting low frequency vibrations like simple body movements, flowing blood, the beating of the heart, the movement of the wind, into electricity. To read more about that go here. (c) tPC