Study on improving current generating time of piezoelectric energy harvesting system

Abstract

This study combined a ceramic, metal alloy, and polymer in a piezoelectric energy harvesting system. The proper container film for curing the urethane rubber was determined to be a Si-coated polyester film. Furthermore, a technique was developed to embed a piezoelectric energy system in urethane rubber (soft and hard); the resulting effects on the output voltage generation of this system were experimentally determined. Comparing the uncoated and hard urethane rubber-coated systems, the latter system improved the energy generation time by a factor of 50 by restricting the recovery time of the metal alloy and storing applied mechanical energy in urethane rubber, providing more time for the piezoelectric ceramic to generate output current. From the LED lighting test results, the urethane rubber coating increased the usable voltage generating time from 0.05 s to 2.5 s. The improved generating time is useful for piezoelectric energy harvesting systems with irregular ambient energy sources.