A bending-bending mode piezoelectric actuator based on PIN-PMN-PT crystal stacks

Piezoelectric actuators are important elements for compact actuations with high precision; however, driving voltage reduction is demanding for integration and minimization of precision actuations. In this work, we proposed a bending-bending mode piezoelectric actuator based on multilayered Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PIN-PMN-PT) single crystals. Ultrahigh apparent piezoelectric coefficient d₃₃ of ~10,800 pC/N is achieved in four crystal stacks. The crystal stacks are used to fabricate bending-bending mode piezoelectric actuators to reduce driving voltage. Experimental results show that it can produce a maximum traveling velocity of 3.28 mm/s under the driving voltage of 130 V_pp at 1000 Hz and minimum step resolution of 0.35 µm with 25 V_pp driving voltage. Conventional piezoelectric actuators require driving voltage of ~300 V_pp for similar motion velocity. This work demonstrates advantages of crystal stacks in piezoelectric actuators and potential applications in low-voltage precise actuations.