Hysteresis-free piezoelectric actuators using LiNbO3plates with a ferroelectric inversion layer

Heat treatment of a bare single-domain lithium niobate plate at somewhat lower temperatures than the Curie temperature causes a local polarization reversal, thereby yielding a ferroelectric inversion layer. The plate with such an inversion layer can serve as a piezoelectric actuator similar to the bimorph, because the piezoelectric constants in the inversion layer are opposite in sign to the original ones. This paper reports the characteristics of the bending actuators using 140° rotated Y-cut LiNbO3. Experimental results show that the actuator characteristics have excellent linearity, no hysteresis, and little creep, and therefore they are suitable for precise position control.