Large Strain Actuation of 0.65PMN–0.35PT/Pt Thick-Film Bimorphs
The effect of clamping a piezoelectric layer to a relatively stiff substrate results in smaller displacements in comparison to substrate-free structures. To ensure a sufficient amount of the bending of actuators, it is important to reduce the thickness of the substrate. For this reason an approach to preparing “substrate-free”, large-displacement actuators using the screen-printing method was developed. The “substrate-free” 0.65PMN–0.35PT/Pt actuators were prepared by screen-printing the 0.65PMN–0.35PT and Pt pastes on alumina substrates. After the screen printing and the subsequent firing the 0.65PMN–0.35PT/Pt composites were peeled off from the substrates. The normalized displacement (the displacement per unit length) of 55 μm/cm at 18 V was achieved, which is approximately five times higher than the displacement of related actuators from the literature.