Study of MEMS Touch-Mode Capacitive Pressure Sensor Utilizing Flexible SiC Circular Diaphragm: Robust Design, Theoretical Modeling, Numerical Simulation and Performance Comparison

Copious research has been conducted on Capacitive Pressure Sensors over the decades with a focus on Silicon being the primary filming element. However, due to Silicon Carbide emerging as superior in harsh environmental conditions, the research is gravitating towards it for industrial applications. This work presents a new analytical model for a polycrystalline silicon carbide-based capacitive pressure sensor working in touch-mode operation. Carbide demonstrates properties like electrical stability, mechanical robustness and chemical inertness which puts it on the frontier of research. The mathematical model proposed is a simple yet powerful tool in manipulating design and sizing for fast analysis. It is quicker and bypasses the need for complex simulation software. The analysis is purely mathematical and hence the results are analyzed with MATLAB. The mathematical model developed is verified with a standard Finite Element Analysis (FEM) using COMSOL v5.2. The results of the mathematical analysis dovetail well with the FEM analysis and show a significant improvement in both the sensitivity and capacitance generated.