Static analysis and simulation of piston coupled diaphragm for microelectromechanical systems based high sensitive sensors
In this work, a new type of diaphragms called ‘piston coupled diaphragm’ is introduced to use as mechanical structure of sensors and micro-electrostatic actuators. Using the static theory based on Kirchhoff–Love theory of plates, expression of deflection is derived. It is assumed that the connection bar area is rigid and simulation results show accuracy of deflection expression. In order to use piston coupled diaphragm as mechanical structure of sensors, electrical and mechanical sensitivity, dynamic range and linear behaviour of the diaphragm are studied. The results show that by choosing a proper dimension of piston coupled diaphragm, because of increased centre rigidity the mechanical sensitivity will decrease but because of realisation of piston-like movement in mechanical structure electrical sensitivity improved by factor of about three in compression to conventional simple diaphragm with the same dimensions and also minimum detectable pressure is improved and linear behaviour of diaphragm degrades. An expression to describe linear behaviour of diaphragm up to 0.54% error from linear response is derived.