Micropower source based on piezoelectric polymers

Abstract

Parasitic harvesting of energy from environment is being investigated as a possible solution for powering electronic devices. One possible solution is to harvest energy generated from human walking, by placing a piezoelectric elements inside footwear. As the amount of available energy is extremely low, conversion effectiveness is of prime importance. This paper deals with a micropower source, designed to harvest energy from walking, built in a form of a shoe insole containing a piezoelectric material (43 μm thick polyethylene foil). Laboratory investigation of the piezoelectric properties is presented first, followed by a measurement result of an actual generator with 0·6 μW output power. Finally, a modification of the generator, by adding springy elements, is presented, resulting in ninefold increase in power output (to 5·6 μW).