Note: Low sliding friction piezoelectric motor using motion of hula hoop

A piezoelectric motor that imitates the motion of a hula hoop was developed. It has the advantage of low sliding wear as static friction force is used to drive the rotor. The rotation speed of the rotor can be regulated by changing the exciting frequency of piezoelectric transducers. The stator is composed of four piezoelectric plates attached to a steel rod. Two orthogonal bending modes were excited by driving two pairs of piezoelectric plates, and circular motion was formed on the rod. The reversed motion of the rotor can be obtained by adjusting the phase of two bending modes. The prototype stator working at 39.1 Hz produced a rotation speed of 1142 rpm and a torque of 0.23 mN m. Published by AIP Publishing.