Body Vibrations Produce Electric Energy

 by Bruce Goodman

“Energy harvesters” are tiny devices that could generate enough electricity from arbitrary, non-periodic noise and vibrations to power a watch, heart pacemaker, or wireless sensor.  Examples include traffic driving on bridges, machinery operating in factories, and humans moving their limbs.  The prototype from U of M’s Engineering Research Center for Wireless Integrated Microsystems is one cubic centimeter in size, uses a material that produces a charge when it is stressed, and can generate up to 0.5 milliwatt from typical human body vibration (enough to run a watch).