Mechanical Structural Design of a Piezoresistive Pressure Sensor for Low-Pressure Measurement: A Computational Analysis by Increases in the Sensor Sensitivity

Abstract

This paper proposes a novel micro-electromechanical system (MEMS) piezoresistive pressure sensor with a four-petal membrane combined with narrow beams and a center boss (PMNBCB) for low-pressure measurements. The stresses induced in the piezoresistors and deflection of the membrane were calculated using the finite element method (FEM). The functions of the relationship between the dimension variables and mechanical performance were determined based on the curve fitting method, which can provide an approach for geometry optimization of the sensor. In addition, the values in the equations were varied to determine the optimal dimensions for the proposed membrane. Then, to further improve the sensitivity of the sensor, a series of rectangular grooves was created at the position of the piezoresistors. The proposed diaphragm was compared to existing diaphragms, and a considerable increase in the sensitivity and a considerable decrease in nonlinearity error could be achieved by using the proposed sensor. The simulation results suggest that the sensor with the PMNBCB structure obtained a high sensitivity of 34.67 mV/kPa and a low nonlinearity error of 0.23% full-scale span (FSS) for the pressure range of 0–5 kPa. The proposed sensor structure is a suitable selection for MEMS piezoresistive pressure sensors.

Development of high-sensitivity piezoresistive pressure sensors for −0.5…+0.5 kPa

“…of MS of different signs. Although reactive ion etching (RIE) of silicon is widely employed for fabrication of chips for ultra-low pressure ranges [16][17][18][19][20][21], the membrane structure is formed using wet anisotropic etching without use of RIE from either the top or back side of the chip.…”

Investigation of Potting-Adhesive-Induced Thermal Stress in MEMS Pressure Sensor

“…Wang et al [ 7 ] introduced an acoustic pressure sensor with an integrated vacuum cavity that could measure pressure without an external package. Tran et al [ 8 ] designed a novel MEMS piezoresistive pressure sensor for low-pressure measurements which had four independent petal membranes. This structure increased the sensitivity and decreased the nonlinearity of the sensor.…”

The piezoresistive properties research of SiC thin films prepared by RF magnetron sputtering

“…The silicon piezoresistive pressure sensors have been widely applied in many different fields, such as automotives, biomedical monitoring, aerospace, 1 ocean detection, 2 industrial applications, 3 and so on, attributing to their high sensitivity, low nonlinearity error, and small size. 4,5 However, the small self-energy band of 1.12 eV limits the applications of silicon sensors from the demands of more than 200 • C. 6,7 In order to improve the operating temperature range of sensors, wide bandgap materials (e.g., diomand, GaN, silicon carbide) have been attracting more attention. Silicon carbide (SiC) is one of the most promising large energy bandgap materials in high-temperature owing to large Young's modulus, high carrier mobilities, high breakdown voltage and compatibility with advanced micro-electro-mechanical system (MEMS) and integrated circuit (IC) process.…”