A micro-capacitive pressure sensor design and modelling

Abstract

Abstract. Measuring air pressure using a capacitive pressure sensor is a robust and precise technique. In addition, a system that employs such transducers lies within the low power consumption applications such as wireless sensor nodes. In this article a high sensitivity with an elliptical diaphragm capacitive pressure sensor is proposed. This design was compared with a circular diaphragm in terms of thermal stresses and pressure and temperature sensitivity. The proposed sensor is targeted for tyre pressure monitoring system application. Altering the overlapping area between the capacitor plates by decreasing the effective capacitance area to improve the overall sensitivity of the sensor ( C/C), temperature sensitivity, and built-up stresses is also examined in this article. Theoretical analysis and finite element analysis (FEA) were employed to study pressure and temperature effects on the behaviour of the proposed capacitive pressure sensor. A MEMS (micro electro-mechanical systems) manufacturing processing plan for the proposed capacitive sensor is presented. An extra-low power short-range wireless read-out circuit suited for energy harvesting purposes is presented in this article. The developed read-out circuitry was tested in terms of sensitivity and transmission range.

Bioresorbable Electronic Implants: History, Materials, Fabrication, Devices, and Clinical Applications

“…Despite its simplicity, the piezoresistive pressure sensor has some disadvantages, including temperature‐related variations in sensitivity . These problems can be solved in capacitive pressure sensors.…”

Flexible Textile-Based Pressure Sensing System Applied in the Operating Room for Pressure Injury Monitoring of Cardiac Operation Patients

“…In general, the working principle of pressure sensors can be classified into three major types: capacitive [ 13 ], resistive [ 14 ], and piezoelectrical [ 15 ]. Among the applications to monitor the interfacial pressure of the human body, the capacitive type pressure sensor on a flexible substrate is the most promising candidate with advantages of high sensitivity and comfortability [ 13 , 16 ]. Due to the natural properties of a flexible substrate, the major interference of these pressure sensors can be the cross-talk from mechanical stress induced by the neighboring area [ 17 ].…”

Large area flexible pressure/strain sensors and arrays using nanomaterials and printing techniques

“…These became outdated for the fabrication efforts and saturation attained for the maximum utility that could be exploited. The early stage sensors were focused in implementing unmanned machining for checking the dimensionality, quality and orientation of work tools in machines, its monitoring and checking wear and breakage using vibration sensor [4, 6–8]. Figure 2 shows typical MEMS based pressure sensor devising a silicon wafer patterned for a diaphragm and electrode using lithography and doping based etching technique.

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