High-Sensitivity Fiber Bragg Grating Pressure Sensor With a Hinged-Lever Structure

This paper presents a high-sensitivity fiber Bragg grating (FBG) pressure sensor with a metal diaphragm and hinge-lever structure designed for small-range pressure measurement. The sensor employs hinge groups and dual-lever structure to amplify the small strain induced by diaphragm deformation, thereby enhancing sensitivity. The sensor structure is analyzed and optimized by the finite element method. The sensor is fabricated, and tested on a pressure calibration platform. The experimental data show that the pressure sensitivity of the sensor is 3.382 pm/kPa in the range of 0-1 MPa, and the correlation coefficient is 0.9999. Another FBG is employed to compensate for the influence of temperature with a sensitivity of 12.14 pm/°C in the range of 20-70 °C, and the correlation coefficient of 0.9998. In addition, the sensor is capable of maintaining stable pressure measurements within the temperature range of 25-55°C. The sensor with high sensitivity and stability is suitable for low-pressure, high-sensitivity detection.