Piezo- and pyroelectricity in polymer electrets and their applications

Typical thin film polymer space charge electret materials are polytetrafluoroethylene (FEP). The corresponding dipolar electret materials are polyvinylidene fluoride, PVDF, its copolymer with trifluoroethylene P(VDF-TxFE), odd nylons and several copolymers of vinylidene cyanide, VDCN. The dipolar electrets display piezo- and pyroelectric responses. The present paper reviews briefly the properties of PVDF, P(VDF-TxFE), odd nylon and VDCN electrets and some applications.