A 3-DOF Piezoelectric Micromanipulator Based on Symmetric and Antisymmetric Bending of a Cross-Shaped Beam

A three degrees of freedom (3-DOF) piezoelectric micromanipulator (PEMMR) based on symmetric and antisymmetric bending of a cross-shaped beam is proposed in this article. Different from typical scheme of combining piezoelectric stack actuator (PSA) and flexible mechanism in previous micromanipulation devices, this article only utilizes eight piezoelectric ceramic plates to construct actuation units and further to realize 3-DOF motions; it overcomes the disadvantages of complex structure, high capacitance and relatively high cost of traditional micromanipulation devices constructed on PSAs. The structure design and motion principle are presented, and the finite-element analysis method is used to simulate output motions and analyze output characteristics; then a prototype is fabricated and an experimental system is established to implement experiments. The experimental results show that the prototype achieves operating range of 99.28 × 99.09 × 24.19 μm, displacement resolution of 15.74 nm, output force of 57.76 mN and force resolution of 0.067 mN, which successfully verifies the design and analysis. The static capacitance of the PEMMR is only about 13.34 nF per axis. Furthermore, a preliminary application experiment is implemented, in which the non-contact posture adjustment of microsphere with diameter of 500 μm in liquid is successfully achieved by the developed PEMMR.