A twist vibrator includes a piezoelectric bimorph which vibrates at a fist end thereof in a twisting direction, and a rigid block connected to a second end of the bimorph. The rigid block restrains the second end from being deformed.
There is described a rotary motor in which a rotor disc is driven by a plate-like driving member comprising a laminate of piezoelectric material sandwiched between outer layers of anisotropic material. When a voltage is applied to the rotor disc the driving member expands into driving contact with the rotor disc and--at the same time--owing to the anisotropy of the outer layers, twists with a torsional movement and this torsional movement imparts a rotary movement to the rotor disc.
