Formulation Analysis and Follow-Up Study of Differential MEMS Touch-Mode Sensor Utilizing Capacitive Vacuum Gauge Framework for Low-Pressure Measurements

Differential capacitance diaphragm gauges have become more popular in pressure measurements, as they yield superior sensitivity and lesser nonlinearity for pressure differential measurements. In addition, differential capacitance diaphragm gauges do not require a high vacuum reference cavity, which reduces their manufacturing complexity. An efficient analysis for modeling differential capacitance diaphragm gauges is, thus, increasingly becoming vital due to their innumerable use cases. The higher sensitivity of circular diaphragm for the same side length in comparison with square diaphragm makes it ideal for sensor design. In this work, a complete formulation for the analysis of differential capacitive vacuum gauge with the circular diaphragm in normal- and touch-mode operations has been presented for the low-pressure range of (1–1500 Pa). A comprehensive study of sensor parameters, such as capacitance, diaphragm deflection, capacitive, and mechanical sensitivity, has been formulated to aid the choice of sensor characteristics. Computationally complex methods have been used in the past for the analysis of circular diaphragms. MATLAB and COMSOL have been used to compute and simulate results.