A Self-Moving Piezoelectric Actuator With High Carrying/Positioning Capability via Bending-Resonant-Vibration-Induced Stick-Slip Motion
Jinshuo Liu, Zhaochun Ding, Jiang Wu, Lipeng Wang, Teng Chen, Xuewen Rong, Rui Song, Yibin Li
Abstract
A self-moving piezoelectric actuator (SMPA) with high carrying/positioning capability is presented in this article. Its Π-shaped mechanical part comprises four piezo-legs, each of which combines the bending vibrations in the first three orders into the motion in the quasisawtooth waveform at the driving foot. Besides, a homemade onboard circuit is integrated with the mechanical part to form compact structure. Initially, by establishing a Krimhertz-transmission-theory-based model, the piezo-leg's resonant frequencies of the 1st, 2nd, and 3rd bending modes were structurally tuned to be approximately 1:2:3. Subsequently, a prototype with the size of 75 × 55 × 55 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and the weight of 38.5 g was fabricated to assess its moving/carrying/positioning performance. At 2065 Hz frequency, SMPA in a tethered manner yielded the maximal payload of 1130 g (equal to 29.3 times of its weight), the maximal speed of 224.1 mm/s, and the maximal towing force of 1.24 N. In an untethered manner, SMPA provided planar movements when receiving the command wirelessly, and it produced the minimal step displacements and the maximal running distance of 12.2 nm and 9.16 m, respectively. Benefiting from the two-DOF untethered movement, SMPA is potentially applicable to the robotic-assistant precise operation, e.g., cell puncture.