A disk–pivot structure micro piezoelectric actuator using vibration mode B11

Abstract

Micro piezoelectric actuator using vibration mode B 11 ( B mn , where m is the number of nodal circles, n is the nodal diameters) is designed. Different from conventional wobble-type ultrasonic motor using piezoelectric rod or cylinder, piezoelectric disc is used to excite wobble modes and metal cylinder stator is used to amplify the transverse displacement, metal rod rotor is actuated to rotate. The outer diameter of the actuator is 14 mm. There are features such as low drive voltage, micromation, and convenient control of wobble state by modifying the structure of stator, etc. Finite element analysis (FEA) of the stator has been made. It is found that the resonant frequency of vibration mode B 11 is 49.03 kHz, which is measured at 45.7 kHz by the laser vibrometer and impedance analyzer. The rotation speed has been measured, which could be as high as 10,071 rpm under an alternating current 100 V. Such piezoelectric actuator can be optimized and adjusted to fit practical conditions. It can be applied in the fields of precise instrument, bioengineering and other micro actuator system.