Development of a high-resolution, high-speed impact piezoelectric actuator using cross-frequency band method

A novel impact piezoelectric actuator is proposed in this paper to achieve cross-scale driving, which can realise high resolution and high speed. The piezoelectric actuator is mainly composed of four diamond-shaped flexible hinges, which can consider a certain stiffness and flexibility. The operating principle of the piezoelectric actuator is introduced. The actuator is excited by two sinusoidal waves with a frequency ratio of 1:2 to achieve impact drive at quasi-static state. The appropriate structural parameters are obtained by simulation. The actuator is designed to make the frequency ratio of first and second vibration modes 1:2, which can achieve impact drive at resonant state. The prototype is fabricated, and the characteristics are tested. The measured resonant frequency ratio is consistent with the simulated value. Experimental results show that when the prototype works at quasi-static state, the resolution is 37 nm with driving voltages of 12 V_p-p; at resonant state, the no-load maximum speed is 125.43 mm s⁻¹ and the maximum load is 0.5 N when the driving frequency and voltages are 1.95 kHz, 40 V_p-p and 3.90 kHz, 160 V_p-p, respectively. The proposed actuator can be used for precision positioning and can improve the accuracy and the efficiency of processing instruments.