Methods to improve energy conversion efficiency of dielectric elastomer generators

Abstract

Dielectric elastomer generators (DEGs) are based on the electromechanical response of the dielectric elastomer film sandwiched between the compliant electrodes on each side, which are capable of converting mechanical energy from diverse sources (e.g, ocean wave) into electrical energy. In essence, DEG is a voltage up-converter using mechanical energy to increase the electrical energy of the charge on a soft capacitor. We evaluated the effect of input voltage and pre-stretch ratio on the energy conversion efficiency of DEG. With a power supply of 2.2 kV and a pre-stretch ratio of 2, the maximum net electrical energy density and energy conversion efficiency in a single harvesting cycle were measured to be 413 J/kg and 15.8%, respectively. The experimental results show that, with the higher input voltage and the larger stretch ratio range, higher the energy conversion efficiency of DEG can be achieved.