A Spatial Deployable Three-DOF Compliant Nano-Positioner With a Three-Stage Motion Amplification Mechanism

This article presents the design, analysis, and prototype test of a novel spatial deployable three-degree of freedom (DOF) compliant nano-positioner with a three-stage motion amplification mechanism (MAM). Inspired by deployable structures, a new design concept, namely monolithically spatial compliant mechanism (MSCM) is proposed to minimize the overall structure. Based on MSCM, a folding operation is employed uniquely by arranging three typical kinds of basic MAM modules with two sets of hooke joints. Due to the spatial structure, the dimensions in horizontal plane is reduced by 60.94%. Furthermore, the proposed nano-positioner demonstrates the simultaneous design of large-ratio amplification mechanism, compact, highly flexible, and assembly-free spatial XY platform with integrated Z platform. Analytical modeling is carried out, and finite element analysis is conducted to optimize the geometric parameters. A prototype is fabricated to verify the performances of the nano-positioner through tests. Experimental results demonstrate that the maximum displacements in x-, y-, and z-axes can reach 177.33, 179.30, and 17.45 \mum, respectively. The motion amplification ratios in the x- and y-axes can reach 10.19 and 10.30, respectively. Moreover, by adopting proportional-integral-derivative feedback controller, the closed-loop control experiments are conducted. The results show that the motion resolution in three axes can all reach 5 nm. As the MSCM has been verified to be feasible and favorable, it can be anticipated that the design concept will contribute to the multiformity and development of compliant mechanisms.