A simple analytical relationship for the efficiency of a constant charge dielectric elastomer energy harvesting cycle is derived for the case of pure shear. The relationship takes into account the nonlinear nature of elastomer materials and the effects of electrically induced strains during relaxation. It is explicitly shown that efficiency is dependent on the applied strain, the shape of the stress-strain curve, and on a lumped parameter (Z') containing the applied electric field, stiffness and permittivity. We show that any term in the lumped parameter can be offset by the other terms; thus a stiff material may require a higher permittivity or electric field to attain the same efficiency as a similar soft material.

Date Published: 3 April 2012
PDF: 6 pages
Proc. SPIE 8340, Electroactive Polymer Actuators and Devices (EAPAD) 2012, 83401W (3 April 2012); doi: 10.1117/12.915372

Published in SPIE Proceedings Vol. 8340:
Electroactive Polymer Actuators and Devices (EAPAD) 2012
Yoseph Bar-Cohen, Editor(s)