In his first accepted submission, Anon8---) writes "As published
on nature.com, a process called electrowetting, 'in which a
conductive liquid droplet, placed on an electrode, is physically
deformed by an applied electric charge,' could be used to
provide 10 watts of juice to smartphones and other gadgets as
you walk. 'The technique depends on the use of a dielectric
material — which is usually an insulator but that can be
polarized in an electric field — to coat the electrode. When the
dielectric is charged the droplet can wet the surface more
easily, and deforms. In his system, Krupenkin runs this process
backwards, using the changing physical form of liquid drops
between dielectric-coated plates to generate charge and
therefore electrical power.' So far, Krupenkin and Ashley Taylor
have been able to produce a few milliwatts of power along tiny
channels a few millimeters wide. They have patented the idea and
are now concentrating on scaling up the device and designing a
shoe to contain it."