Nonlinear analysis of micro-electromechanical flow sensors

Abstract

Micro-Electro-Mechanical (MEM) sensors have been used in various applications such as drug discovery, disease diagnosis, detection and characterization of materials, detection of fluid flow parameters, etc. With these devices, sensing is commonly achieved via detection in change of stress/strain/mass with beam static deflection/frequency. In the present study, the behavior of a MEM flow sensor under electrostatic as well as external mechanical loading due to crossflow of non-viscous fluid is modeled. Hamilton’s principle was used to derive the governing equations and the numerical solution was obtained with MATLAB code via finite difference. The model is studied with respect to the basic controllable parameters such as voltage input, initial gap, and maximum flow velocity. The results show that nonlinear relationship exists between the velocity of the moving fluid and the pull-in voltage of cantilever beam. Thus, with proper calibration the velocity of the fluid at any instant can be obtained.