Designing of optimum silicon piezo resistive micro cantilever of flow meters using genetic algorithm

This paper presents a new high sensitive micromechanical silicon cantilever beam with a u-shape integrated strain gauge on its surface for optimizing piezo resistive read out. To improve the sensitivity of micro cantilever sensors, this study analyses and compares the deflection, vibration characteristics and maximum stress of rectangular and trapezoidal profile micro cantilevers. Therefore a new micro cantilever is designed with trapezoidal profile that is more sensitive than conventional ones. The surface stress is modelled as in — plane tensile force applied on the top of the micro cantilevers. ANSYS software is used as a tool to design and model the mechanical properties of the silicon-based micro cantilevers. The Euler — Bernoulli beam model and stony formulas are used to calculate the surface stress moment and deflection. For selecting the highest sensitive micro cantilever beam we optimize dimensions of tapered beam by genetic algorithm. The simulation results are very promising.