三维纳米级微动工作台的设计与分析

研究开发了一种新型精密三维微动工作台。采用呈等边三角形分布的三个压电陶瓷和环形平板铰链机构 ,保证了运动传递的连续性、无洄滞、无摩擦、高精度。建立了工作台的简化模型,并利用结构力学理论推导出工作台沿z方向平动刚度、绕x、y方向转动刚度以及前三阶固有频率解析式。进行了微动工作台沿z方向平动刚度、绕x、y方向转动刚度以及固有频率试验测试,验证了解析方法和有限元方法进行三维工作台刚度及动力特性分析的正确性。有限元分析表明:当工作台的环形平板铰链半径较小而铰链厚度较大时,其刚度、频率及驱动力较高,其铰链根部应力集中也较严重。通过改变环形平板铰链的特征参数,可达到控制和优化工作台固有频率、输出位移、应力分布及驱动力响应的目的,并提出了一种优选微动工作台环形平板铰链参数的简易方法。

Design and analysis of a novel 3-DOF nanopositioning stage

A novel three-degree-of-freedom(3-DOF) nanopositioning stage was developed.The stage utilizes three piezoelectric actuators(PZTs) arranged in an equilateral triangle shape and ring plate hinges to realize nanopositioning for assuring smoothness of movement,negligible friction,negligible backlash and high precision.The simplified modeling of the nanopositioning stage was discussed.The translational stiffness along z direction and rotational stiffness along x and y direction,and three natural frequencies of the nanopositioning stage are deduced in terms of the theory of structural mechanics.Theoretical analysis and finite element analysis on static and dynamic behavior of the nanopositioning stage are performed.The comparative results of the theoretical analysis,finite element analysis(FEA) and experiments show the accuracy of theory model and the validity of FEA.FEA also indicates that the stiffness,the natural frequency and the driving force will increase with decreasing hinge radius and increasing hinge thickness despite the maximum stress increasing of the stage.By modificating the dimensions of a ring plane hinge it can control and optimize natural frequency,displacement,stresses,and driving force to achieve the desired response of the nanopositioning system. Finally,this paper gives a simple procedure to select the proper dimensions of a nanopositioning stage.