Optimal Design of the Electrothermal V-Beam Microactuator Based on GA for Stress Concentration Analysis

 Abstract—The stress concentration of the electrothemal microactuator is an important issue in the MEMS structure resulting from the existence of stress concentration essentially to change the performance and reduce the structural life time of MEMS devices. This paper proposes a method to optimize the fillet radius of the electrothermal V-beam microactuators due to bent beam connected with electrical pad. The genetic algorithm combines with the finite element method to design the optimal fillet radius of bent beam. A novel design of the fillet radius on V-beam actuator can significantly improve the stress concentration. In this study, we use the proposed method to design the beam width and thickness to obtain the relative minimum stress, firstly. Then, the optimal fillet radius can achieve by using the same method at the given beam width and thickness. The results show that the stress concentration can be reduced about 57.7% after optimization.

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