A compliant parallel mechanism with flexure-based joint chains for two translations

Abstract

A compliant parallel mechanism for two translations is proposed and applied to a XY fine motion stage driven by piezo actuators. Four flexure-based prismatic-prismatic joint chains are arranged in four sides of a target platform to implement the compliant parallel mechanism. Among others, two are passive joint chains for only motion guidance, and the others are active joint chains for motion guidance merging the function of the displacement amplification of a piezo actuator. Due to the active joint chains, the proposed mechanism has more compact structure than the others which have the separated mechanisms of the motion guidance and the displacement amplification. In addition, the compliant mechanism has a monolithic structure not to be assembled. The compliant mechanism is designed, verified to satisfy some design constraints using Finite element Analysis, and then combined with piezo actuators and capacitance sensors. The characteristics and the performance of the piezo-driven compliant parallel mechanism are demonstrated by experiments.