Determination of optimal crystallographic orientations for LiNbO ₃ and LiTaO ₃ bimorph actuators

The actuators for precise positioning based on bimorph structures of piezoelectric LiNbOinline-formula₃ and LiTaOinline-formula₃ crystals are considered. The optimal orientations of the actuator plates ensuring the highest possible displacements are determined by the extreme surfaces technique and the finite-element method. The simulated displacements for optimal orientations of LiNbOinline-formula₃ and LiTaOinline-formula₃ plates are compared with those obtained experimentally for manufactured LiNbOinline-formula₃ and LiTaOinline-formula₃ actuators, whose orientations are not optimal. As is shown, the optimal configuration of the actuator allows us to significantly increase its displacement for both LiNbOinline-formula₃ and LiTaOinline-formula₃ specimens.