Effective polarization fatigue from repeated dielectric barrier discharges in cellular polypropylene ferroelectrets

Polarization fatigue is observed when cellular polypropylene (PP) ferroelectrets are subjected to high-voltage cycles. The fatigue rate strongly depends on the amplitude and the number of the applied voltage cycles, whereas the frequency and the waveform of the voltage do not have a strong influence. The much lower piezoelectric activity of significantly fatigued cellular PP ferroelectret films recovers in part after a storage period of typically several hours in ambient air. It is believed that the effective polarization fatigue is mainly caused by the plasma modification of the internal surfaces effected by the repeated dielectric barrier discharges inside the voids. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2998597]