Design and analysis of symmetrical, monolithic tip-tilt-piston flexure stages

This paper mainly deals with the determinate design/synthesis of a class of symmetrical and monolithic flexure mechanisms. Each is composed of 6 identical in-plane wire beams with uniform square cross sections. These flexure stages can provide three out-of plane tip-tilt-piston motions for applications in high-precision or miniaturisation environments. A generic symmetrical structure is proposed as first with a group of defined parameters considering constraint and non-interference conditions. Normalised static analytical compliance entries for the diagonal compliance matrix of a generic structure are derived and symbolically represented by the parameters. Comprehensive compliance analysis is then followed using the analytical results, and quick insights into effects of parameters on compliances in different directions are gained. Case studies without and with actuation consideration are finally discussed. As a second contribution, a physical prototype with three actuation legs is monolithically fabricated (using CNC milling machining), kinematically modelled and experimentally tested, which shows that the desired out-ofplane motion can be generated from the in-plane actuation.