A brief overview of various piezoelectric actuators - electromechanical converters of electrical signals of the power source into movement is given. An electromechanical mathematical model of a piezoelectric torsional-bending TorsBC-actuator in the form of a curved two-layer bimorph of torsion from two fi lm piezoelectric IncIDE-actuators with orientation angles ±π/4 interdigital electrodes was developed. The working bending of the TorsBC actuator in the transverse plane is due to controlled piezoelectric twisting around its longitudinal curvilinear axis. The torque is due to piezoelectric tensile or compressive stresses at ±π/4 angles to the longitudinal axis in the bimorph layers. The polarity of the control voltage applied to the electrode outputs determines the sign of the piezoelectric stresses (i.e. tension or compression in directions ±π/4) of the torsion bimorph layers and, as a result, determines the direction of twisting and the resulting transverse bending of the TorsBC actuator. Analytical solutions and numerical analysis of values of deflection, twist angle and blocking force on free end of cantilever arc-shaped TorsBC actuator are obtained depending on its geometrical and electro-mechanical parameters, in particular, curvature of its longitudinal axis. The results are relevant in the design of bending-type sensors and actuators, elements of microelectromechanical systems, stepper motors and manipulators for assembling microscale objects.
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