There’s something intrinsically logical about harvesting the energy that we create by walking so that we can power up some of the gadgets that we have on our person all the time. These InStep Nanopower shoes will do something like this, and they actually use liquid metal to get the job done.

Researchers Tom Krupkin and J. Ashley Taylor at UW-Madison have been working on this technology and it looks like it will be able to deliver 10 to 20W of power. This is a lot more than the electri...