电热微执行器与柔性放大机构的刚度匹配分析

Stiffness match between electro-thermal micro-actuators and compliant amplifiers

针对电热微执行器和柔性微杠杆位移放大机构连接时二者刚度失配会严重影响工作性能的问题,将微执行器和微杠杆机构等效成两个弹簧连接的模型,对其刚度关系进行了理论分析,并用有限元方法进行了仿真。结果显示,执行器和微杠杆机构的刚度比值极大地影响整个机构的输出特性。用负载线方法给出了两种柔性机构连接时进行刚度匹配设计的直观解释。最后,用深层反应离子刻蚀(DR IE)技术在硅隔离衬底(SOI)上成功制作了微执行器和组合机构样机,并对其进行了测试,测试结果与理论分析结果符合很好。

Stiffness mismatch between electro-thermal actuator and the attached micro leverage severely ruins the performance of their combination. This paper analyzes the stiffness relationship between them theoretically and finite element method （FEM） is used to carry out simulation. This combined structure is simplified as a model of two springs connected in series. The results show that the stiffness ratio of the micro-actuator and the micro leverage significantly affects the output performance of the system. In addition, the load line method is used to explicitly explain the stiffness match design between two compliant mechanisms. In the end, prototypes were fabricated on silicon-oninsulator （SOI） wafer with deep reactive ion etching （DRIE） technology and tested. The test and analytical results well coincide with each other.