Noncontact planar stage based on near-field acoustic transportation

Acoustic radiation force in the near-field of a vibrating source can be utilized to lift and transport objects, which provides a noncontact driving technology in addition to maglev. This paper presents a novel design of a self-levitated planar stage based on near-field acoustic transportation. A closed-loop system is proposed to design a capacitance surface encoder to provide direct two-dimensional (2D) position feedback. A dynamic model based on the Reynolds equation is established to study its driving mechanism. A prototype including the levitation stage, encoder, and controller is implemented to demonstrate the potential of arbitrary trajectory tracking in two-dimensional space.