A Wide Range and High Repeatability MEMS Pressure Sensor Based on Graphene

Abstract

Graphene pressure sensors have attracted extensive attention due to their excellent performance. However, the range and linearity of conventional suspension graphene pressure sensors are too small to meet commercial requirements. In this article, we propose a wide range and high repeatability MEMS pressure sensor based on graphene array structure. Single-layer chemical vapor deposition (CVD) graphene was transferred at the root of silicon pressure-bearing elastic diaphragm, and it was simultaneously protected by the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanofilm. In addition, the Au/Sn eutectic bonding technology was employed to complete the hermetic package of the sensor. Pressure tests showed that the repeatability error of the pressure sensor in the range of 0–20 MPa was 4.062% full scale output (FSO) and the hysteresis was 2.118% FSO. Furthermore, the temperature resistance studies confirmed that the Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanofilm can effectively protect graphene due to its extremely high thermal stability. And with excellent characteristics of high long-term stability, it can work stably in humid environments. Conclusionally, this research provides significant exploration to promote the practicality and commercialization of graphene devices.