Correlation Improvement Between Theoretical and Experimental Results of PZT Thin-Film Membrane Actuators

This paper is to study actuation displacement of a Lead Zirconate Titanate (PbZr_xTi_1−xO₃ or PZT) thin-film membrane actuator via finite element modeling and laser-Doppler measurements. In particular, this paper is to identify possible parameters that could cause discrepancies between the finite element predictions and experimental measurements. A twofold approach is used. First, we conduct additional experiments to measure actuator dimensions, which are subsequently used as input to the finite element model. We also measure natural frequencies of the membrane actuators to compare with the finite element predictions in addition to the actuator displacement. Second, we have conducted a parametric study via the finite element model to identify possible parameters that could cause the discrepancies. Parameters varied include dimensions, material properties, residual stresses and linearity of the PZT thin-film membrane actuator. Simulation results indicate that the residual stresses are the most probable cause of the discrepancy between the theoretical predictions and the experimental results.