Piezoelectric d₃₆ in-plane shear-mode of lead-free BZT-BCT single crystals for torsion actuation

We report the study of piezoelectric direct torsion actuation mechanism using lead-free piezoelectric d₃₆ in-plane shear-mode BZT-BCT single crystals. The generated angle of twist of the piezoelectric torsion actuator was obtained from the transverse deflection measurement using a laser vibrometer. The bi-morph torsional actuator, consisting of two lead-free piezoelectric BZT-BCT in-plane shear-mode single crystals with a giant piezoelectric d₃₆ shear strain coefficient of 1590 pC/N, provided a rate of twist of 34.12 mm/m under a quasi-static 15 V drive. The experimental benchmark was further modelled and verified by the ANSYS software using three dimensional (3D) piezoelectric finite elements. The experimental results revealed that lead-free piezoelectric BZT-BCT d₃₆-mode single crystal is a superior candidate for piezoelectric torsion actuation. This lead-free piezoelectric BZT-BCT d₃₆-mode torsion actuator can be effectively applied in torsional deformation control by taking into account the environmental considerations.