Micro-motion Stage Research Articles

A three‐DOF compliant micromotion stage with flexure hinges

Micromanipulation has enabled numerous technological breakthroughs in recent years, from advances in biotechnology to microcomponent assembly. Micromotion devices commonly use piezoelectric actuators (PZT) together with compliant mechanisms to provide fine motions with position resolution in the nanometre or even sub‐nanometre range. Many multiple degree of freedom (DOF) micromotion stages have parallel structures due to better stiffness and accuracy than serial structures. This paper presents the development of a three‐DOF compliant micromotion stage with flexure hinges and parallel structure for applications requiring motions in micrometres. The derivation of a simple linear kinematic model of the compliant mechanism is presented and simulation results before and after calibration are compared with results from finite element (FE) modeling and experiments. The position control system, which uses an experimentally determined constant‐Jacobian, and its performance are also presented and discussed.

Inverse kinematic modeling of a coupled flexure hinge mechanism

An inverse kinematic model of a micro-motion stage with three degrees-of-freedom motion is presented. The XYθ stage uses three piezoelectric actuators and a monolithic flexure hinge mechanism which is designed to provide large θ motion. The stage design has a coupled hinge mechanism which causes a difficulty in motion control. This paper describes a computer based inverse kinematic model of hinge mechanism and the experimental verification for the model. In particular, it presents a kinematic calibration procedure for improving the accuracy of the model. It is shown that the simulation and experimental results are very similar to each other and they also demonstrate that the inverse kinematic model can be used for open loop control of the stage within 5% error. The open loop control of the stage provides 7.6 and 8.2 nm positioning resolution over the total range of 41.5 and 47.8 μm along the X- and Y-axis, respectively, and 0.057 arcsec rotational resolution over the total range of 322.8 arcsec about the θ-axis.

Optimal design of a flexure hinge based XYφ wafer stage

Optimal design o1 a XYφ micromotion stage is presented. The stage consists of a monolithic flexure hinge mechanism with three piezoelectric actuators. This paper describes the procedures of selecting parameters for the optimal design. In particular, it presents a mathematical formulation of the optimization problem. Based on the solution of the optimiiation problem, the final design of the stage is also presented. Experimental results indicate that the design procedure is effective, and the designated stage has the total range of 41.5 μm mid 47.8 μm along the X- and Y-axes, respectively, and the maximum yaw motion range of 322.8 aresec (1.565 mrad).