Dynamic characteristics of functionally gradient piezoelectric actuators

Functionally gradient materials (FGM) for application in monolithic microdisplacement actuators were investigated. Recently, we developed a novel type of monolithic piezoelectric bender-a resistivity gradient piezoelectric actuator (RGPA) based on PZT piezoelectric ceramics doped with the donor La³⁺ and acceptor Fe³⁺ respectively. The RGPA consists of three layers with different resistivities: a high resistivity layer, a low resistivity layer and a middle diffusion layer whose resistivity changes across the thickness gradually. We proposed a model in which the three layers display the same mechanical boundary conditions. According to the model, the dynamic behavior of the RGPA was analyzed and measured with good agreement between predicted and measured results