A high performance hybrid-driven piezoelectric actuator based on asymmetrical structure with combined lateral and coupling motions

Bionic stepping piezoelectric actuators such as stick–slip or inchworm actuators demonstrate important applications in semiconductor manufacturing and active optics, where high-speed and high-precision motion capabilities, as well as load performance, often involve a trade-off arising from distinct actuation mechanisms. This study proposes a compact piezoelectric actuator based on biomimetic driving principles combining the advantages of stick–slip and inchworm actuations by employing only two piezoelectric stack units. The design comprises a multifunctional driving foot based on a flexible triangular mechanism and a clamping foot based on a spring hinge. The asymmetrical structure features displacement amplification and enables combined lateral and coupling motions, supporting a hybrid driving principle to achieve both stick–slip and inchworm motions from a performance perspective. A prototype of the designed piezoelectric actuator was fabricated to verify its feasibility and performance. The experimental results show that the actuator achieves a maximum speed of 52.89 mm/s and a maximum output force of 24.52 N, with a motion resolution of 23 nm, which significantly outperform existing results in the literature.