Sensitivity Enhancement of FBG-Based Strain Sensor

Area of Science:

• Optical Sensing
• Mechanical Engineering
• Materials Science

Background:

• Fiber Bragg Gratings (FBGs) are widely used for strain sensing.
• Enhancing the sensitivity of FBG sensors is crucial for micro-strain measurements.
• Existing FBG sensors may lack sufficient sensitivity or dynamic range for certain applications.

Purpose of the Study:

• To develop a novel high-sensitivity Fiber Bragg Grating (FBG)-based strain sensor.
• To enhance the strain sensitivity of FBG sensors using a mechanical lever structure.
• To investigate the theoretical and experimental performance of the developed sensor.

Main Methods:

• Designing and fabricating an FBG sensor integrated with a lever-based mechanical amplification structure.
• Developing and validating a theoretical model for the strain-amplifying mechanism.
• Conducting experimental tests to measure strain sensitivity and dynamic characteristics.
• Utilizing Finite Element Method (FEM) for dynamic characteristic analysis.

Main Results:

• The developed FBG strain sensor achieved a high strain sensitivity of 6.2 pm/με.
• The sensor's sensitivity is 5.2 times greater than that of a bare FBG sensor.
• The sensor demonstrated a high resonant frequency and a wide dynamic working range due to its high-stiffness mechanical configuration.
• Experimental results closely matched theoretical predictions.

Conclusions:

• The novel lever-structured FBG sensor significantly enhances strain sensitivity.
• The sensor offers a high dynamic range and resonant frequency, suitable for harsh environments.
• This high-sensitivity FBG sensor is a promising solution for micro-strain measurements in industrial applications.