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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.

Capacitive pressure sensors (CPSs) have become more prevalent compared to the piezoresistive pressure sensors because they generate superior sensitivity and better linearity for the same application. Due to the innumerable use cases of the CPSs, it is becoming increasingly critical to carry out efficient analysis for their modeling. The higher sensitivity of a square diaphragm for the same side length in comparison to a circular diaphragm makes it ideal for sensor design. In this work, a complete formulation for analysis of a CPS with a square diaphragm having a linkage film has been presented. A comprehensive study of sensor parameters like capacitance, deflection of the diaphragms, capacitive and mechanical sensitivity has been formulated to aid the choice of sensor characteristics. This work also focuses on the method to determine the fundamental design parameters for optimal operation. Complex and resource-expensive methods have been used in the past for the analysis of MEMS capacitive pressure sensors. MATLAB and ANSYS have been used to compute and simulate the results.

Due to advancements in Micro-Electro-Mechanical Systems (MEMS) fabrication technologies, researchers are incorporating numerous innovations in the design of capacitive pressure sensors (CPS). This work aims to present a novel CPS design using a plano-convex substrate to enhance the capacitance and sensitivity. Diaphragm deflection occurs due to its elastic property when pressure is applied to the diaphragm. This deflection reduces the distance between the diaphragm and substrate, thereby remarkably increasing capacitance. The Plano-Convex design offers added advantages of increased contact area between the diaphragm and substrate under applied pressure, hence significantly enhancing sensor sensitivity and range. More efficient and miniaturized CPSs are in high demand in medical instrumentation, aerospace, aviation, power plants and automotive industries. This work presents all the required mathematical calculations, modeling and simulations to support the proposed design. The diaphragm deflection simulation concerning pressure is conducted using COMSOL Multiphysics, while MATLAB is employed for analytical simulations related to changes in capacitance and capacitive sensitivity.