The ultrasonic motors (USM) based on microelectromechanical systems (MEMS) technology utilize the inverse piezoelectric effects to drive the rotor through the friction force to realize the torque output. Therefore, the generation of a stable traveling wave within the stator is a key to USM performance, which heavily depends on the quality factor ( Q ) and the mode match level of a stator resonator. The current ring stators of micromotor exhibited an apparent mode mismatch and a relatively low Q value due to the displacement constraints and anchor loss of supporting beams. This article, through the modal analysis and energy dissipation evaluation of stators, proposes an elaborate design to improve the mode match and Q value by positioning the supporting beams at the saddle points of the B ₁₃ modal shape and introducing a buffering annular frame between beams and substrate. The designed stator has the natural frequency of 101.63 and 100.90 kHz and Q value of 89.5 obtained from the finite element method. And the prototype experiment shows the natural frequencies of two modes are 100.76 and 101.5 kHz, respectively, the maximum deflection of the stator under driving voltage of 0.5 and 1 V are 3.96 and 4.43 μ m, respectively, and the Q value is 84.58. Both the frequency and rotation tests indicate the proposed motor displays, a much higher Q , and extremely better mode match than current ones.

中文翻译：

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一种具有高Q值和良好模式匹配的压电微超声电机

基于微机电系统（MEMS）技术的超声波马达（USM）利用逆压电效应通过摩擦力驱动转子实现扭矩输出。因此，在定子内产生稳定的行波是 USM 性能的关键，这在很大程度上取决于品质因数（ Q ) 和定子谐振器的模式匹配水平。微电机的电流环定子表现出明显的模式失配和相对较低的由于支撑梁的位移约束和锚固损失，Q 值。本文通过定子的模态分析和耗能评估，提出了一种精心设计以改善模态匹配和通过将支撑梁定位在支架的鞍点处获得 Q 值 B ₁₃模态形状并在梁和基板之间引入缓冲环形框架。设计的定子固有频率为 101.63 和 100.90 kHz，从有限元方法获得的 Q 值为 89.5。样机实验表明，两种模式的固有频率分别为100.76和101.5 kHz，在0.5和1 V驱动电压下定子的最大偏转分别为3.96和4.43μ m，分别为 Q 值为 84.58。频率和旋转测试都表明建议的电机显示，更高Q ，以及比当前模式更好的模式匹配。