An inertial bipedal piezoelectric actuator with integration of triple actuation modes

Piezoelectric actuators based on inertial principle have been widely studied and applied in ultraprecision fields due to their simple structures. In this work, we proposed a bipedal piezoelectric actuator, which could work in synchronous inertial actuation mode (SIAM), bipedal alternating inertial actuation mode (BAIAM) and inertial impact actuation mode (IIAM). The step size, motion speed and carrying load are measured, and the rollback ratios are calculated to evaluate the displacement linearity. The experimental results confirm that SAIM has a simple exciting strategy, BAIAM has a smooth motion and IIAM has better load characteristics. The rollback ratio working in BAIAM is 0.7% and that is 14.4%, 69% in SIAM and IIAM, respectively, which proves that BAIAM effectively improves the displacement linearity. When working in IIAM, the load mass varying from 100 g to 350 g, the speed does not change significantly (the maximum variation range is 4% compared with 23% in SAIM and BAIAM under 0–500 g load). The developed actuator can switch between the triple actuation modes by changing the excitation signal to obtain compatible performance, it has potential in applications where large range, stable carrying load capacity and smooth motions are required, such as cell surgery and micromanipulation.