Research on the Micro-Stator of a MEMS Traveling-Wave Motor Based on the Air-Damping Loss Model

The traveling-wave motor of a micro-electro-mechanical system (MEMS) is a micrometer-scale actuator, which is an ideal solution to miniaturize inertial guidance systems. In view of that, this study proposes a low air loss micro-stator actuator of a traveling-wave motor operating in the
${B}_{{15}}$
mode with an outer diameter of 6 mm. The proposed micro-stator structure has 20 support beams and 20 electrodes and is stacked as a Pt electrode, a lead zirconate titanate (PZT) layer, and a top silicon substrate. In addition, to compare the losses of different structures and achieve fast structural selection and performance optimization, this study proposes an air-damping loss simulation model. This model quantifies the resonance loss of the structure in the air by wrapping the micro-stator actuator with an air layer, thus achieving an accurate estimation of the quality factor of the structure. Further, two structures operating in the
${B}_{{15}}$
and
${B}_{{13}}$
modes are constructed and used for the simulation analysis and experimental tests. The results demonstrate that the structure operating in the
${B}_{{15}}$
mode exhibits superior performance compared to that operating in the
${B}_{{13}}$
mode. The quality factor of the micro-stator actuator is 565, which is more than two times higher than that of the micro-stator structure with the currently highest-reported quality factor. The resonant frequencies of the two standing waves are 118.62 and 118.64 kHz, with a mode-matching degree of 99.9%. When excited by a 10-V signal, it generates a torque of up to
$42.2 \mu \text{N}\cdot \text{m}$
, and the rotor speed can reach 7800 r/min.