Impact of boundary conditions and geometric tolerances dynamics on MEMS double touch mode capacitance pressure sensor applying M-shaped silicon design.

Micro-Electro-Mechanical Systems (MEMS) are extensively utilized in many different applications because of its compact design, low power consumption and greater sensitivity. Compared to piezoresistive alternatives, a MEMS- based Touch Mode Capacitive Pressure Sensor (TMCPS) is designed and simulated to achieve better sensitivity, stability and linearity. This work presents a Double Touch Mode MEMS-based Capacitive Pressure Sensor (DTMCPS) with a flexible circular diaphragm integrated into an M-shaped silicon substrate. By increasing the diaphragm-substrate contact area, the proposed M-shaped structural arrangement improves sensor linearity and sensitivity. The diaphragms deflection characteristics are modeled using small deflection theory to minimize nonlinearity. A comprehensive analysis of the sensors capacitive behavior is carried out. The analytical formulations for capacitance, capacitive sensitivity and mechanical sensitivity are derived and generated using MATLAB based simulations. The diaphragm deformation is further assessed through structural analysis using COMSOL Multiphysics. The goal is to improve the performance of the conventional DTMCPS by integrating a silicon (Si) circular diaphragm with an M-shaped silicon substrate. The position of the touch point is crucial in defining the overall sensitivity, hence the notch size have a considerable impact on the sensors operational properties. Small deflection theory is used to model the diaphragm behavior in order to minimize nonlinear effects. These results show the potential use in cutting edge medical, automotive, aerospace and industrial sensing applications by demonstrating the higher sensitivity, accuracy and durability of the preferred TMCPS design.