A high-speed inchworm piezoelectric actuator with multi-layer flexible clamping: Design, modeling, and experiments

In this study, we propose a bidirectional high-speed inchworm actuator driven by two PZT stacks by employing innovative flexible symmetric clamp feet with a multilayer structure design, where the switching of the clamp feet is performed by a single PZT. In addition, the symmetric clamp foot design synchronizes the clamping forces and improves the efficiency of the driving mechanism. The drive principle is analyzed, and a model on the clamping performance with respect to the single-step length is developed based on the compliance matrix method. A numerical analysis is conducted to verify the proposed model and optimize driving performance. The experimental results demonstrate that the proposed actuator achieves high-speed and stable bidirectional motion with a maximum speed of 43.8 mm/s and a maximum driving force of 3 N at a driving frequency of 150 Hz, which significantly outperforms existing results. The experiments also demonstrate that the motion resolution of the proposed actuator is 1.57 nm with a large travel range (25 mm in this particular design). The innovative design of the PZT inchworm actuator promises various applications in precision engineering with high-speed and large range nanomanipulatons.