Compliant mechanism optimization: analysis and design with intrinsic characteristic stiffness

This article focuses on design formulation of compliant mechanisms posed as a topology optimization problem. With the use of linear elasticity theory, a single-input, single-output compliant mechanism is represented by the stiffness matrix of its structure with respect to the input-output ports. It is shown that the stiffness model captures the intrinsic stiffness properties of the mechanism. Furthermore, in order for the optimization problem to be properly defined, it is necessary that the stiffness matrix of the mechanism's structure must be guaranteed to be always positive definite. An exploratory design formulation is then presented based on this necessary condition. Numerical examples are provided to illustrate the potential benefits of using the intrinsic stiffness properties for compliant mechanism design with topology optimization techniques.