On understanding of design problem formulation for compliant mechanisms through topology optimization
General problems associated with the design of compliant mechanisms through the topology optimization technique are defined in this paper due to the lack of comprehensive definitions for these problems in the literature. Standard design problems associated with rigid body mechanisms, i.e. function generation, path generation and motion generation, are extended to compliant mechanisms. Functional requirements and the associated 25 formulations in the literature are comprehensively reviewed along with their limitations. Based on whether the output is controlled quantitatively or not, these formulations are categorized into two types: (1) formulations for quantitative design; and (2) formulations for qualitative design. In addition, formulations that aim to solve the point flexure problem are also discussed. Future work is identified based on the discussion of each topic.