Development of 1mm Cylindrical Piezoelectric Micromotor

A piezoelectric micromotor with diameter of 1mm and length of 5mm is developed. The motor is basically composed of a solid cylindrical metal stator and rotor. Two surfaces of the metal cylinder stator were polished at an angle of 90° with respect to each other and two uniformly rectangular piezoelectric patches were bonded onto the flat orthogonal surfaces with epoxy resin. The rotor made of brass metal is pressed against on the stator by its elastic deformation. The finite element model and simulations of the stator was carried out by a finite element analysis code, ANSYS to verify the mode shapes generated at the resonance frequencies. The influences of the system parameters on the vibration characteristics of the stator were also conducted. The designed resonance frequency of the developed motor is 17 kHz. The length of the stator increases will greatly decrease the resonance frequency and the thickness of the PZT patches will increase the resonance frequency. The elliptic trajectory is obtained when two orthogonal AC voltages were applied on the two PZT patches, and the maximum vibration displacement is 15.6 um when the excited voltage is 100V. Due to the basically two parts, the developed motor is simple and easy to fabricate compared with other motors, it can be used in scanning fiber endoscopy.