Numerical analysis of reaction forces at the supports of sliding microwire

Abstract

The reaction forces at the tungsten support probes of a platinum microwire are determined by numerical analysis for different push-pull sliding velocities and contact pressures. The Finite Element Analysis (FEA) tool ANSYS Workbench is used to evaluate the contact stresses, reaction forces and deformations of the platinum microwire. The nonlinear contact analysis and contact formulations are implemented to ensure that the platinum microwire maintained contact with the tungsten support probes during push-pull sliding motion, and transfer frictional forces between contact surfaces without penetration and separation. The reaction forces at the support probes are found independent of the sliding velocity of the platinum microwire and vary with normal contact pressure. The results found in the numerical analysis are validated through experimental works. Due to the tiny size, the nonlinearity of contacts and indeterminate supports criteria, it is difficult to determine the reaction forces at the supports of a sliding microwire by conventional mechanics. The method of the numerical analysis of the sliding microwire presented in this paper can be used to determine the reaction forces of other microstructures, validate the experimental results, as well as to evaluate total disturbance forces in the microstructures where relative motion exists; which are important for the proper design and failure analysis of the MEMS devices and microstructures.