Liquid-crystal-based fiber laser sensor for non-invasive gas detection

Area of Science:

• Optoelectronics
• Chemical Sensing
• Biomedical Engineering

Background:

• Acetone in breath is a key indicator for diabetes management.
• Existing breath acetone sensors face challenges with accuracy, response time, and temperature sensitivity.

Purpose of the Study:

• To develop a novel, ultra-compact, and fast-response optical fiber gas sensor for quantitative breath acetone measurement.
• To address the temperature sensitivity of liquid crystals in sensing applications.

Main Methods:

• Utilizing photonic bandgap (PBG) mode laser emission sensing technology.
• Integrating silica fiber with chiral nematic liquid crystal (CNLC).
• Implementing a temperature-compensation method to eliminate thermal influence on measurements.

Main Results:

• Achieved accurate and quantitative determination of respiratory acetone concentration.
• Demonstrated a linear correlation of 0.99 between acetone detection and dual laser peak splitting.
• Reported a limit of detection of 65 ppm for acetone vapor.
• Validated sensor performance within the normal oral temperature range (35-38°C).

Conclusions:

• The developed optical fiber sensor offers a promising solution for non-invasive breath acetone monitoring.
• The sensor's design provides a fast response, high accuracy, and temperature stability.
• This technology is suitable for breath acetone detection in diabetic patients, aiding in disease management.