A High-Power-Density Piezoelectric Actuator Operating in Bicycling Movement Mechanism

Comprehensive high-precision actuations are in growing demand to meet diversified needs in scientific and industrial fields. However, it is a great challenge for piezoelectric actuators with compact structure to guarantee high load capacity and wide velocity range (including fast motion velocity and high resolution) simultaneously. Herein, inspired by bionic methodology, a high-power-density bar-type linear piezoelectric ultrasonic actuator (LPUA) operating in the single second bending (
B₂
) mode with elaborate working principle is developed by imitating bicycle movement mechanism. The proposed
B₂
-LPUA actuator is simple and easy for miniaturization without multimodal decoupling problem. Under only one-phase voltage drive, the miniature bar-type actuator can produce continuously bidirectional motions with the maximum driving velocity, minimum driving velocity, load, and output power of 211.2 mm/s, 3.3
μ
m/s, 5.4 N, and 218.3 mW, respectively, and the tested minimum step displacement is only 33 nm in open-loop control. Especially, its output power density (243 mW/cm
³
or 4.112 mW/cm
³
⋅kHz) is at least twice larger than most reported LPUAs. The experimental results indicate that the proposed piezoelectric actuator with excellent actuation performances has broad application scenarios, and its bionic motion design method would have inspirational significance for creating new piezoelectric devices with more attractive properties.