Optimizing the Dimensions of an Inverse-Magnetostrictive MEMS Pressure Sensor by Means of an Iterative Finite-Element Scheme

Abstract

This paper proposes an iterative finite-element scheme that accounts for the inverse-magnetostrictive (Villari) effect. To do so, the permeability of magnetostrictive materials is updated according to the internal mechanical stress of the material at the end of each iteration step until convergence is reached. VSM measurements of prestressed thin-film samples are used to evaluate the stress-dependent permeability. Using the implemented scheme, it is possible to optimize the dimensions of inverse-magnetostrictive microelectromechanical pressure sensors with a view to maximum sensitivity. Such sensors feature a sandwichlike structure with a planar coil embedded between two magnetostrictive layers. To date, only insufficient simulation results regarding the optimization of such devices have been published. We present the results of simulations incorporating the inverse-magnetostrictive effect that show the influence of the dimensions of single layers on the overall sensitivity.