Development of a Monopod Piezoelectric Robot for Small Parasitic Displacement and Planar Cross-Scale Locomotion

In order to broaden the application of micro-nano positioning, the actuator needs to have characteristics of high precision, large stroke, low coupling error, and simple control. However, the existing piezoelectric platforms or robots cannot well meet these requirements. Therefore, this article proposes a monopod piezoelectric robot to improve precision motion ability for cross-scale locomotion. The robot has the decoupling characteristic of a parallel compliant mechanism in structure. It outputs static displacement through the deformed compliant mechanism and continuous motion through the stick-slip principle. The response deviation among multiple legs is avoided by one drive leg. Moreover, parallel compliance mechanisms and elastic buffer structures reduce parasitic motion. The size of the proposed robot is 84.3 mm × 84.3 mm × 38 mm. The experimental results show that it has a low coupling error (0.26%), high motion accuracy (<5%), and simple control. This robot has two-degree-of-freedom planar motion, nano-scale resolution (17 nm), millimeter-scale speed (2.98 mm/s), and good speed robustness against the payload. The robot has been applied to optical alignment, and two fibers with diameter of 250 μm are aligned successfully.