Abstract: Topology optimization methods of compliant mechanisms are presented. Firstly, the ground structure method and the homogenization method are discussed. The models of optimiza-tion are obtained. Two material models are discussed for the homogenization method. Secondly, the extraction process and two filter algorithms are presented. One of the algorithm is based on the calculation of the element filter density, the another one is based on the calculation of the nodal density. The former is valid for post process, and the latter is valid in the design process. Finally, the key problems need to be solved in the field are pointed out.

Key words: Compliant mechanism, Filter, Ground structure, Homogenization, Topology optimization