Achieving low-frequency and high-speed motion based on bionic seal principle for piezoelectric actuator

In this paper, a novel stepping piezoelectric actuator with a compact structure is proposed, which is based on bionic seal principle. It consists of a bridge-type amplification mechanism (BAM) and a diamond-shaped amplification mechanism (DAM). The control signal adopts the square wave, so that the BAM and the DAM move in coordination, and the mechanism drives the mover without backward motion. Through theoretical analysis and finite element analysis (FEA), the displacement magnification ratio of the structure is calculated, and the size of the structure is preliminarily optimized. Finally, a test prototype is made for experimental verification. According to the experiment, urged by the input signal with the frequency of 2 Hz and the amplitude of 150 V to the BAM and DAM, the maximum speed of forward and reverse are 229.2 μm/s and 212.25 μm/s, respectively. It can reach a resolution of 42.1 nm in forward motion and 204.7 nm in reverse. When the load in the vertical direction reaches 50 N, it can still output a stable displacement motion curve. According to the displacement-time curves and the calculation of the moving speed under different voltages, frequencies, and loads, it is proved that this actuator has good low-frequency and high-speed driving performance.