Design and testing of a new 3-DOF spatial flexure parallel micropositioning stage

This paper presents the design and testing of a novel 3-DOF parallel flexure micropositioning stage for micro-scale operations. The proposed modular design can obtain the merit of high interchangeability during maintenance process. The output platform of the mechanism offers pure translational motion along X, Y, and Z axes by resorting to the flexure guiding of two parallelogram joints. Meanwhile, the output motion is decoupled by using two leaves with symmetric ellipse-shaped flexure hinges, and the platform provides isolated movement without parasitic motion. By using the bridge-type and lever-type compound amplifier, the micropositioning stage provides a large output displacement, which is over 30 times the input displacement provided by piezoelectric actuator. The enlarged displacement is translated to the orthogonal parallel mechanism by four straight beams, which provide perfect decoupling properties. In addition, the modular design principle makes it possible to adopt multiple materials to balance the performance of the actuator and decoupling flexure hinges. Analytical analysis and finite element analysis simulation are conducted to verify the fine decoupling property and large translational motion of the proposed 3-DOF parallel micropositioning stage. Moreover, a prototype is fabricated using multiple materials for experimental testing. Results demonstrate the promising performance of the developed decoupled micropositioning stage.