摘要Piezoelectric actuators are widely utilized in positioning systems to realize nano-scale resolution.However,the backward motion always generates for some piezoelectric actuators,which reduces the working efficiency.Bionic motions have already been employed in the field of piezoelectric actuators to realize better performance.By imitating the movement form of seals,seal type piezoelectric actuator is capable to realize large operating strokes easily.Nevertheless,the con-ventional seal type piezoelectric actuator has a complicated structure and control system,which limits further applications.Hence,an improved bionic piezoelectric actuator is proposed to realize a long motion stroke and eliminate backward movement with a simplified structure and control method in this study.The composition and motion principle of the designed actuator are discussed,and the performance is investigated with simulations and experiments.Results confirm that the presented actuator effectively realizes the linear movement that has a large working stroke stably without back-ward motion.The smallest stepping displacement ΔL is 0.2 μm under 1 Hz and 50 V.The largest motion speed is 900 μm/s with 900 Hz and 120 V.The largest vertical and horizontal load are 250 g and 12 g,respectively.This work shows that the improved bionic piezoelectric actuator is feasible for eliminating backward motion and has a great working ability.