A Millimeter-Scale Ultrasonic Motor Applied to Micro Swimming Robot

In this paper, a micro ultrasonic motor using two orthogonal bending modes is designed, fabricated, and characterized. This motor is mainly composed of two dual rotors and one stator bonded by rectangle piezoelectric ceramics to excite the stator's orthogonal bending modes. The operating principle of the motor design is to utilize the coupling of the orthogonal bending modes to drive rotor. The stator has a diameter of 2.6mm and a weight of 0.338 gram. The vibration characteristics and output performance of the motor are tested. The no-load speed of t the prototype of the motor can be reached 7000 rpm under the driving voltage 180 Vp-p at the driving frequency of 103.6 kHz. The proposed millimeter-scale ultrasonic motor provides a new driving method for micro pipeline swimming robot.