A Bio-Inspired Parallel Ultrasonic Manipulation Platform with 3-DOF Motions, Fast Speed and High Resolution

Conventional ultrasonic platforms typically rely on multi-mode degeneracy within a single elastic structure and single-foot for actuation, necessitating mechanical guides to ensure motion stability. However, these guides restrict the expansion of motion degrees of freedom (DOFs), particularly rotational motion. Inspired by the four-leg coordinated actuation mechanism of the traditional Chinese lion dance, this study proposes a parallel ultrasonic platform employing four vertically mounted piezoelectric actuators with the degeneracy of longitudinal and bending modes. This configuration enables stable X, Y, and Θ_z DOF actuation without the need for mechanical guidance. Furthermore, driving redundancy is introduced by configuring an angular deflection between actuators, allowing the platform to trade-off between speed and resolution. In fast mode, the platform achieves linear and rotational speeds of 285 mm s⁻¹ and 380° s⁻¹, respectively, while in precise mode, it attains resolutions of 90 nm and 40 µrad. Mode switching is accomplished simply by adjusting the driving signals. Finally, wafer inspection and cellular observation experiments are carried out as proof-of-concept demonstrations of the suitability of the platform for basic micro-operation tasks.