Dielectric and piezoelectric properties of stacked and plated PVDF, P(VDF/TeFe), P(VDF/TrFE) and ceramic/rubber composite thick films

We measured the properties of nine different piezoelectric materials, as supplied, and as further processed to increase their hydrostatic sensitivity. We studied the effect of electrode material, stiffening plates, and multiple layering on the piezoelectric and dielectric properties of the thick piezopolymer films. Dielectric measurements and thickness mode d/sub 3t/, lateral mode d/sub 31/(d/sub 32/), and hydrostatic mode d/sub h/ piezoelectric coefficients were measured at different stages of the films' processing into layered stacks. The polymer films were bonded together to produce two-layer and three-layer thick films. Metal stiffening plates bonded to the films' outside surfaces inhibit lateral response and hence improve hydrostatic voltage response. The highest sensitivities result from the thickest P(VDF/TrFE) samples with the lowest dielectric constants and stiffest clamping plates.