Tom Krupenkin and J. Ashley Taylor, University of Wisconsin–Madison, USA, describe a mechanical-to-electrical energy conversion method based on the reverse electrowetting phenomenon.
150 droplets, arranged in-between novel nanometer-thick multilayer dielectric films, generate electricity when pressed upon and moving around. So far this setup has netted only a few milliwatts of power. A few thousand of those together could generate enough power to juice up gadgets, including cell phones.

InStep NanoPower, LLC, Madison, Wisconsin, USA, aims to commercialize the technology by planting the small reverse electrowetting generators in shoe soles.

• Reverse electrowetting as a new approach to high-power energy harvesting,
  Tom Krupenkin, J. Ashley Taylor,
  Nature Communic. 2011, 2, 448.
  DOI: 10.1038/ncomms1454