A walking type piezoelectric actuator with two umbrella-shaped flexure mechanisms

A walking type piezoelectric actuator with two umbrella-shaped flexure mechanisms is proposed to reduce the backward motion. By utilizing two umbrella-shaped flexure mechanisms which could be treated as two 'legs', the 'walking' motion is accomplished. The structure and motion principle are described; Finite Element Method (FEM) is exploited to explore the static and modal performances of the umbrella-shaped flexure mechanism. Moreover, experiments have been carried out to investigate the working performance of the proposed walking type piezoelectric actuator. Results show that the walking type piezoelectric actuator with umbrella-shaped flexure mechanisms could achieve the 'walking' motion and reduce the backward motion. Additionally, the phase difference between two input signalsU(1)andU(2)greatly influences the working performance. In the case of the phase difference phi= 95 degrees, the backward rate of the slider is able to achieve the minimum 0%; the minimum stepping displacement is 0.3 mu m when the frequencyf= 1 Hz; the maximum motion speed of the slider is up to 1132 mu m s(-1)when the input frequencyf= 400 Hz and the input voltageU= 120 V; the maximum output force is 700 g while the input voltageU= 120 V and frequencyf= 1 Hz.