Theoretical Modelling and Simulation of Circular Diaphragm-based Comb Drive Capacitive Pressure Sensor (CD-CDCPS)

## Theoretical Modelling and Simulation of Circular Diaphragm-based Comb Drive Capacitive Pressure Sensor (CD-CDCPS)

© 2022 by IJETT Journal
Volume-70 Issue-5
Year of Publication : 2022
Authors : Maibam Sanju Meetei, Heisnam Shanjit Singh, Rakesh Sharma, Ningthoukhongjam Vikimchandra Singh
DOI :  10.14445/22315381/IJETT-V70I5P206

How to Cite?

Maibam Sanju Meetei, Heisnam Shanjit Singh, Rakesh Sharma, Ningthoukhongjam Vikimchandra Singh, "Theoretical Modelling and Simulation of Circular Diaphragm-based Comb Drive Capacitive Pressure Sensor (CD-CDCPS)," International Journal of Engineering Trends and Technology, vol. 70, no. 5, pp. 37-45, 2022. Crossref, https://doi.org/10.14445/22315381/IJETT-V70I5P206

Abstract
The mathematical modeling and simulation of circular diaphragm-based comb drive pressure is demonstrated in this work. The fundamental configurations of capacitors for use as sensors are discussed. A step-by-step design flow process is established for building a diaphragm-based comb-drive capacitive pressure sensor. The modeling is divided into two parts: mechanical and electrostatic. In mechanical, the deflection of the circular diaphragm is calculated, and in electrostatic, the change in capacitance is formulated rather than the absolute capacitance because finding the absolute capacitance for such a complex structure is extremely difficult. The sensor`s 3D model is simulated in the COMSOL Multiphysics simulator, confirming the mathematically determined result. Physical dimensions of the diaphragm and inter-digited finger of the comb, Young`s modulus, and Poison`s ratio of the diaphragm material are among the factors that can improve CD-CDCPS sensitivity. For a diaphragm thickness of 25 µm, the sensitivity of the circular diaphragm-based comb-drive capacitive pressure for simulated and calculated is 0.192 fF/MPa and 0.235 fF/MPa, respectively.

Keywords
Comb-drive, Deflection, Linearity, Sensitivity, Touch-mode, Sensitivity.

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