A novel linear piezoelectric actuator with two working principles of standing and traveling wave vibration mode

This paper presents a new linear piezoelectric actuator, which consists of two pieces of piezoelectric ceramics, a copper substrate and a zirconia driving tip. By changing the input signal, the actuator can be chosen to work in a standing wave mode (two-phase vibration modes coupling) or in a traveling wave mode (four-phase vibration modes coupling). By using the Finite Element Method (FEM), the actuator was designed and optimized, and a prototype was fabricated. For a single actuator at 240Vp-p, the maximum no-load velocity and thrust force were approximately 106 mm/s, 1.2 N in the standing wave mode and 161 mm/s, 1.46 N in the traveling wave mode, respectively. While parallel use of four actuators at the same voltage, the experimental results showed that the velocity and force reached 246 mm/s, 2.2 N in the standing wave mode and 292 mm/s, 4.1 N in the traveling wave mode. More importantly, this study shows that both the load performance and the vibration characteristics of the actuators can be improved greatly by working in the traveling wave mode or parallel distribution of multi-identical piezoelectric actuators.