High field poling of poly(vinylidene fluoride) films using a current limiting circuit.
01 January 1984
A high field room temperature poling technique has been developed for preparing poly(vinylidene fluoride), PVDF, films with high piezoelectric activity. The technique utilizes a resistor (typically 5 x 10(7) to 10(11) ohms) which is inserted between the power supply and the polymer film to control the voltage buildup across the polymer film and to limit the current flow through the film in case of incipient breakdowns. Application of the technique to 25 micron-thick biaxially oriented films (with provision to prevent edge flashover) showed that the films could be poled without breakdown failure for a period of one to 10(5)seconds depending on the external resistance and the applied field (up to 12MV/cm).