An analytical model for a twisted beam piezoelectric ultrasonic micromotor

An equivalent circuit, known as a Mason model, is proposed to characterize a novel ultrasonic motor in this study. This motor, which consists of a non-circular cross-section twisted beam and a piezoelectric element, generates coupled longitudinal-torsional vibration upon application of an electric field. The model predictions and experimental data are in good agreement. For example, under the condition of having input voltage of 100 Vpp, and driving frequency of 352.8 kHz, the model predicts a longitudinal velocity of 0.7 m/s compared to the experimental results of 0.65-0.75 m/s. The assumption is that the torsional velocity and longitudinal velocity are in a linear relationship; a proportionality coefficient K=0.259±0.012 is obtained through the experimental data by empirically fitting