Modeling and Analysis for Triaxial Flexure Mechanisms with Symmetric Overconstrained Configurations

Compliant mechanisms have been wildly used in high-precision positioning stages of obtaining in-plane motion. In contrast, the study of multi-axis spatial motion stages shows a deficiency in recent years. In this work, a triaxial translational compliant mechanism design is proposed by employing diverse flexure elements and over-constrained symmetric configuration, which can support high-precision and spatial-decoupling positioning capability. A generalized theoretical model is established to incorporate those utilized flexure elements into a unified framework, and the analytical stiffness model of the triaxial compliant mechanism is also obtained through the compliance transformation matrix method. Furthermore, finite element analysis (FEA) is conducted to verify the analytical results and evaluate the over-constrained symmetric (OS) configuration compared with the nonsymmetric (NS) one. Finally, the characteristics of the stage with symmetric configuration are investigated through a key parameter study. The results show significant potentials in applications such as micro-nano laser direct writing which require multi-dimension and high-precision positioning and alignment of wafer stages.