Development of a 3-DOF in-parallel compliant micro-motion stage for micromanipulation

This paper addresses the design and control issues of a novel micromanipulator which uses a 3-DOF parallel compliant mechanism driven by PZT actuators. Based on the pseudo-rigid-body model of the mechanism, both its conceptual design considerations and the final prototype are outlined first. In order to achieve a fine close-loop control for the PZT, a control law called Variable Speed Integral PI with Switched Parameters is employed based on a simplified but effective dynamic model of PZT actuators. Results from performance testing of the prototype compliant micromanipulator demonstrate that it has repeatability with less than 1 micron. The compliant stage is used as a high-precision bioengineering-oriented micromanipulator.