Inertial Block-Enhanced Stick-Slip Piezoelectric Actuator for Smooth Motion

The stick-slip piezoelectric actuators have the disadvantage of backward motion, which reduces the efficiency of the piezoelectric actuator and triggers problems such as abrasion of the driving foot and will seriously affect the life of the actuator. In this study, a new flexible mechanism with inertial block is proposed. The structural parameters and the trajectory of the driving foot are verified by the finite element method. A prototype of the piezoelectric actuator is fabricated and various experiments on the trajectory of the driving foot and the performance of the actuator are conducted. The experimental results show that the piezoelectric actuator can achieve smooth motion with a maximum motion speed of 5.54 μm/s at f = 1 Hz and U = 100 V with symmetry 0% sawtooth wave drive, while the maximum speed can reach 1278.81 μm/s at f = 3000 Hz and U = 100 V. The piezoelectric actuator can realize a maximum horizontal load of 50 g and a maximum vertical load of 1400 g. The results show that the new flexible mechanism and its driving method proposed in this study are practicable, which can effectively reduce the sliding friction in the rapid rise period and effectively increase the static friction in the slow fall period and can achieve smooth motion with high load capacity and driving frequency. It has certain significance for the performance improvement and market application of piezoelectric actuator.