A New Type of High-Sensitivity Fiber Grating Pressure Sensor

Area of Science:

• Optoelectronics
• Mechanical Engineering
• Sensor Technology

Background:

• Fiber Bragg Grating (FBG) sensors are widely used for various sensing applications.
• Traditional FBG pressure sensors often suffer from bending-induced spectral distortion and limited stability.
• Developing high-sensitivity and stable pressure sensors is crucial for underwater and harsh environment monitoring.

Purpose of the Study:

• To propose and experimentally validate a high-sensitivity FBG pressure sensor.
• To investigate an X-shaped mechanical transducer for converting pressure to axial strain.
• To optimize sensor design for improved measurement stability and reduced spectral distortion.

Main Methods:

• Design of an X-shaped mechanical transducer to convert external pressure into axial strain.
• Development of a theoretical model relating applied force, pressure, and FBG wavelength shift.
• Experimental optimization of Ethylene Propylene Diene Monomer (EPDM) thickness, bonding materials, and contact area.
• Performance evaluation of the sensor for force and underwater pressure measurements.

Main Results:

• Achieved force sensitivities of 0.291 nm/N, 0.409 nm/N, and 0.462 nm/N within 0-10 N.
• Demonstrated high underwater pressure sensitivity of 0.596 nm/kPa within 0-6 kPa.
• Exhibited excellent linearity, repeatability, and stability in sensor performance.

Conclusions:

• The proposed X-shaped transducer effectively converts pressure to axial strain, mitigating bending effects.
• The developed FBG pressure sensor offers high sensitivity and stability for practical applications.
• This approach provides a viable solution for high-performance pressure sensing in challenging environments.