Caltech runs a Summer Undergraduate Research Fellowship (SURF) program where students work on special projects. As part of a cell phone medicine project, the students have spent their summer developing and fine-tuning prototypes that could someday enable a 10-cent medical checkup for developing or remote regions.
We knew it all along: Walking is good for you. While walking we turn 20 Watts of power per foot into heat. But now researchers in Wisconsin have found a way to charge batteries with a firm stride.
Tom Krupenkin and J. Ashley Taylor are using an electrostatic capacitor but “with a conductive solid substrate, which they topped with droplets of an electrically conductive liquid. On top of it they placed a metal electrode coated with a 10- to 50-nanometer-thick film of an insulating material.
“That meant that the gap between the metal electrode and the conductive liquid electrode was a mere 10 to 50 nanometers. The bottom conductive substrate and the top electrode were then connected into a circuit. So when the solid electrode was pushed down, compressing the liquid droplets, or pushed laterally over the top of them, the device produced a very large capacitance and voltage. If scaled up to the size that would fit in a typical shoe, this would enable the Wisconsin researchers to harvest 2 watts of power, they report today in Nature Communications.