Electromechanical behavior of Form I uniaxially and biaxially stretched PVDF

Experiments were carried out on Form I uniaxially and biaxially stretched Polyvinylidene Fluoride (PVDF) samples to characterize their electromechanical response. The piezoelectric constants were measured at different values of superimposed strains or loads and at different values of frequencies of dynamic strains, which were applied in the longitudinal and transverse direction. It was also found through experiments that, the piezoelectric constants of PVDF are affected by the frequency of loading and there seems to be some dependence of the phase difference between the electrical and mechanical response on the superimposed strains. The tests also confirm to some extent, the results obtained by other researchers, that the piezoelectric constants increase in the longitudinal direction with increasing superimposed strains and decrease in the transverse direction for uniaxially stretched PVDF.