Conception and realization of a novel design for a capacitive pressure sensor with high sensitivity and linear response

• Published in: Results in engineering 2022-09, Vol.15, p.100535, Article 100535
• Main Authors: Achouch, Samia, Bousseta, Rihab, Regragui, Fakhita, Gharbi, Mourad
• Format: Article
• Language: English
• Subjects: 3D printing technology; capacitive sensing; linearity; Pressure sensor; sensitivity
• ISSN: 2590-1230; 2590-1230
• DOI: 10.1016/j.rineng.2022.100535

In order to improve the performance (linearity and sensitivity) of capacitive-based diaphragm pressure sensors, a new design is proposed. The non-linearity is improved by eliminating the capacitance of a small area in the central region of the sensor. In contrast, the sensitivity is improved by enhancing the contribution of the edges of the sensor, which leads to a structure where the distance between the fixed and movable diaphragms is non-uniform. Unlike the other research works, we focus on the case of large deflections. The mathematical model allowing the determination of the capacitance as a function of pressure for this new design is presented. Three prototypes with different sized non-metalized central areas are successfully fabricated using 3D printing technology and machining process. Simulation results show that this form allows a non-linearity inferior to 1% if the reference capacitor is variable. •A new design for capacitive pressure sensor based on the modification of the fixed diaphragm.•Improvement of the sensor performances by making the distance between sensor's diaphragms non uniform.•Realization of the proposed design using 3D printing technology and a machining process.