Piezoelectric micromotor using a metal-ceramic composite structure

This paper presents a new piezoelectric micromotor design, in which uniform ly electroded piezoelectric ring bonded to a metal ring is used as the stat or. Four inward arms at the inner circumference of the metal ring transfer radial displacements into tangential displacements. The rotor ends in a tru ncated cone shape and touches the tips of the arms. A rotation takes place by exciting coupled modes of the stator element, such as a radial mode and a second bending mode of the arms. The behavior of the free stator was anal yzed using the ATILA finite element software. Torque vs. speed relationship was measured from the transient speed change with a motor load. A starting torque of 17 mu Nm was obtained at 20 Vrms. The main features of this moto r are low cost and easy assembly because of a simple structure and small nu mber of components.