A Compact Optical MEMS Pressure Sensor Based on Fabry–Pérot Interference

• Published in: Sensors (Basel, Switzerland) Vol. 22; no. 5; p. 1973
• Main Authors: Qi, Yonghong, Zhao, Minghui, Li, Bo, Ren, Ziming, Li, Bing, Wei, Xueyong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 03.03.2022; MDPI
• Subjects: Design; diaphragm; Fabry–Pérot (FP); Glass substrates; Lasers; Light; MEMS; pressure sensor; Sensors; pressure sensor; diaphragm; Fabry–Pérot (FP); MEMS
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s22051973

Pressure sensors have important prospects in wind pressure monitoring of transmission line towers. Optical pressure sensors are more suitable for transmission line towers due to its anti-electromagnetic interference. However, the fiber pressure sensor is not a suitable choice due to expensive and bulky. In this paper, a compact optical Fabry–Pérot (FP) pressure sensor for wind pressure measurement was developed by MEMS technology. The pressure sensor consists of a MEMS sensing chip, a vertical-cavity surface-emitting laser (Vcsel), and a photodiode (PD). The sensing chip is combined with an FP cavity and a pressure sensing diaphragm which adopts the square film and is fabricated by Silicon on Insulator (SOI) wafer. To calibrate the pressure sensor, the experimental platform which consists of a digital pressure gauge, a pressure loading machine, a digital multimeter, and a laser driver was set up. The experimental results show that the sensitivity of the diaphragm is 117.5 nm/kPa. The measurement range and sensitivity of the pressure sensor are 0–700 Pa and 115 nA/kPa, respectively. The nonlinearity, repeatability, and hysteresis of the pressure sensor are 1.48%FS, 2.23%FS, and 1.59%FS, respectively, which lead to the pressure accuracy of 3.12%FS.