Modeling and performance evaluation of a flexure-based XY parallel micromanipulator

This paper presents the modeling and evaluation of a nearly uncoupled XY micromanipulator designed for micro-positioning uses. The manipulator is featured with monolithic parallel-kinematic architecture, flexure hinge-based joints, and piezoelectric actuation. Its performances in terms of parasitic motion, cross-talk, lost motion, workspace, and resonant frequency have been evaluated via analytical approaches. Based on pseudo-rigid-body (PRB) simplification and lumped model methods, the mathematical models for the kinematics and dynamics of the XY stage have been derived in closed-forms, which are verified by resorting to finite element analysis (FEA). Furthermore, a challenging full nonlinear kinematics model is established, which is based on the deformation of the entire manipulator since the above simplified models fail to predict its kinematic performances. The effectiveness of the nonlinear model is validated by both FEA and experimental studies on the prototype. Results show that the nonlinear model can predict the manipulator kinematics accurately, and the reason why simplified models fail is discovered. The established analytical models are helpful for both a reliable architecture optimization and performance improvement of the XY micromanipulator.