Theoretical analysis and simulation of thermoelastic deformation of bimorph microbeams  

作　　者：SHANG YuanFang YE XiongYing FENG JinYang 

机构地区：[1]State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology,Tsinghua University

出　　处：《Science China(Technological Sciences)》2013年第7期1715-1722,共8页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 91023027)

摘　　要：In this paper, a purely mechanical model for the thermoelastic behavior of a bimorph microbeam is presented. The thermoelastic coupling problem of the microbeam is converted to a mechanical problem by simply replacing the thermal stress in the beam with a bulk force and a surface force. Thermoelastic deformation of the bimorph microbeams with constraints frequently used in micro-electro-mechanical systems (MEMS) devices has been derived based on this model and is characterized by FEA simulation. Coincidence of the results from theory and simulation demonstrates the validity of the model. The analysis shows that a bimorph microbeam with a soft constraint and a uniform temperature field has a larger thermoelastic deformation than that with a hard constraint and a linear temperature field. In addition to the adoption of materials with large CTE mismatch,thickness ratio and length ratio of the two layers need to be optimized to get a large thermoelastic deformation.In this paper, a purely mechanical model for the thermoelastic behavior of a bimorph microbeam is presented. The thermoelastic coupling problem of the microbeam is converted to a mechanical problem by simply replacing the thermal stress in the beam with a bulk force and a surface force. Thermoelastic deformation of the bimorph microbeams with constraints frequently used in micro-electro-mechanical systems (MEMS) devices has been derived based on this model and is characterized by FEA simulation. Coincidence of the results from theory and simulation demonstrates the validity of the model. The analysis shows that a bimorph microbeam with a soft constraint and a uniform temperature field has a larger thermoelastic deformation than that with a hard constraint and a linear temperature field. In addition to the adoption of materials with large CTE mismatch,thickness ratio and length ratio of the two layers need to be optimized to get a large thermoelastic deformation.

关 键 词：mechanical model THERMOELASTIC DEFORMATION MICROBEAMS BIMORPH 

分 类 号：TP211.4[自动化与计算机技术—检测技术与自动化装置]