Abstract: A two-degree-of-freedom planar compliant mechanism possesses a workspace that is able to serve as a micromanipulator carrier to generate programmed planar path by controlling two independent inputs. To improve the manufacturability of the compliant mechanism design, shape optimization is investigated on the basis of extracted profile after topology optimization. The profile is abstracted into lined links and crunodes. Based on the principle of connectivity in topology, a condition is set up for judging the connectivity of link domain, and then a translational scanning algorithm using windows is constructed to search the crunodes of the required compliant mechanism in the design domain. On this basis, a link searching algorithm is built in order to locate the lined links for the abstraction of the contour of the compliant mechanism. The contour is reconstructed for the abstracted compliant mechanism. The contour is represented as linked simple curves whose parameters serve as optimized variables. Among these variables key dimensions are determined on the basis of sensitivity analysis. The error between the real output and the desired output of the compliant mechanism is used as objective function to form the optimization model of the contour dimension and then generate optimum contour of the compliant mechanism. This optimization improves the manufacturability of the designs without lowering the motion performance of the compliant mechanism. Case studies are given to demonstrate the effectiveness of the presented shape optimization method for compliant mechanism.

Key words: Compliant mechanism, Contour abstraction, Contour dimensional optimization, Contour reconstruction, Planar path generation, Shape optimization, Topology connectivity, Translational scanning using windows