Wang, Ting-JuiTing-JuiWangYU-HSIANG HSUCHIH-KUNG LEETol, SerifeNouh, Mostafa A.Yang, JinkyuHuang, GuoliangLi, XiaopengChen, YangyangSugino, Christopher2025-07-072025-07-072025-03-17https://www.scopus.com/record/display.uri?eid=2-s2.0-105007429888&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/730604This study developed a miniature self-propelled ultrasonic piezoelectric plate motor designed for precise actuation in a compact structure. This motor was comprised of a 9 mm × 6 mm × 0.3 mm stainless steel plate and a 0.2 mm thick PZT actuator with free edges to avoid complex fixtures. To enable self-propelled motion, the superposition of Φ20 and Φ21 modes was used to generate the traveling waves based on the Two-Integer-Frequency, Two-Mode (TIF-TW) driving method, which drove the motor in the same direction. Since no analytical solution exists for a plate with free boundary conditions, the Rayleigh quotient method was used to approximate mode shapes and resonant frequencies, and finite element analysis (FEA) was performed for validation. A cost function based on the Hilbert Transform was introduced to optimize wave stability and reduce standing wave effects. FEA results confirmed that superimposing Φ20 (26 kHz) and Φ21 (52 kHz) can generate stable traveling waves. With time-dependent simulations, we obtained a consistent wave amplitude range of -3.02 × 10-4 mm to 2.9 × 10-4 mm, ensuring predictable micro-displacements. Our findings demonstrate the feasibility of our proposed ultrasonic piezoelectric plate motor for compact ultrasonic actuation and self-propelled motion.Hilbert transformtraveling wavetwo-integer-frequency two-modeultrasonic piezoelectric motorconference paper10.1117/12.3050574