Reduced graphene oxide for fiber-optic humidity sensing

Area of Science:

• Materials Science
• Sensor Technology
• Nanotechnology

Background:

• Graphene-based electrical chemical vapor sensors exhibit high sensitivity but suffer from slow response/recovery times and limited low-concentration detection.
• Existing sensors are unsuitable for applications demanding rapid detection of high concentrations.

Purpose of the Study:

• To develop a novel graphene-based fiber-optic sensor for relative humidity (RH) detection.
• To address the limitations of electrical graphene sensors in terms of response speed and concentration range.

Main Methods:

• Fabrication of a graphene-based fiber-optic sensor utilizing a distinct sensing mechanism.
• Characterization of sensor performance, including power variation, response linearity, sensitivity, response speed, and repeatability across a high RH range.

Main Results:

• The sensor demonstrated a significant power variation (up to 6.9 dB) in the 70-95% RH range.
• Achieved a linear response (correlation coefficient 98.2%), sensitivity of 0.31 dB/%RH, and a response speed faster than 0.13%RH/s.
• Exhibited good repeatability within the 75-95% RH range.

Conclusions:

• The novel graphene-based optical sensor effectively overcomes the limitations of electrical counterparts for RH detection.
• Theoretical analysis supports the sensing mechanism and suggests potential for detecting other chemical vapors.
• This technology promotes the broader application of graphene in advanced chemical sensing.