Extensions of Spring Model Approach for Continuum-based Topology Optimization of Compliant Mechanisms.

Manish Sharma and Tushar Udeshi
Zyvex Corporation, US

Keywords: Topology Optimization, Spring Model Approach, Multiple Outputs, Compliant Mechanisms

Abstract:
This paper extends spring model approach to include multiple output formulation at arbitrary angles for a given actuation at input port. Parallel assembly for Microsystems could benefit from devices optimized with this formulation. A new constraint is formulated to restrict the motion at the output port in the direction perpendicular to the desired motion direction. A linear-motion microgripper has been designed using this formulation. Structural Topology Optimization software has been developed with commercial code ANSYS as the FE solver and MMA as the optimization solver. The objective functions incorporated include Mechanical Advantage (MA), Geometric Advantage (GA), a linear combination of MA and GA, and Mechanical Efficiency. SIMP material model is used and heuristic filter is implemented for mesh independency of solutions. Designs obtained are imported into ANSYS where they are analyzed for their validity. Some of the designs have been/are being fabricated in micro-scale using SOI DRIE process. Measurements are done using automatic probe station and compared with the results from simulations.

NSTI Nanotech 2003 Conference Technical Program Abstract