Optimal design of electro-thermo-mechanical microactuators considering minimum length scale constraints

To ensure the manufacturability of compliant mechanisms, this paper presents a new approach for optimal design of electro-thermo-mechanical microactuators by employing minimum length scale constraints. A sequential coupling method is adopted to carry out finite element analysis for electric-thermal-mechanical coupling multiphysics. The inflection point fields of the solid and void phases are identified by structural indicator functions. The minimum length scales of the solid and void phases are adopted as constraints. The optimization objective is designed to maximize the output displacements of electro-thermo-mechanical microactuators. The validity of the proposed optimal design method is demonstrated through several numerical examples. In the optimal designs obtained by the proposed method, the minimum length scales of the two phases can be properly controlled. The electro-thermo-mechanical microactuator's output displacements decrease when the allowable value of the minimum length scale is increased. The effects of different mesh discretizations and output spring stiffnesses on the optimized designs are discussed.