Electromechanical response of cellular electret films

Abstract

Charged polypropylene films with a cellular structure show pseudopiezoelectric properties. Measurements of the direct and inverse electromechanical transducer constants of such films, relating to the operation as sensors and as actuators, respectively, yield values of ≈200 pC/N. These values can be explained with a theoretical model by assuming reasonable charge distributions and charge densities. The experimental and the theoretical results show the reciprocity of the transducer constants.