Optical Fiber-Based Polymer Microcantilever for Chemical Sensing: A Through-Fiber Fabrication Scheme

Area of Science:

• Materials Science and Engineering
• Chemical Sensing Technologies
• Optical Fiber Sensors

Background:

• Fiber optics present a promising, yet challenging, substrate for developing advanced chemical and biological sensors due to fabrication difficulties.
• The high aspect ratio of optical fibers complicates the integration of microfabrication techniques required for sensor development.

Purpose of the Study:

• To establish a novel microfabrication platform on optical fibers for creating high-aspect-ratio polymer cantilever sensors.
• To demonstrate the functionality of these polymer cantilevers for dynamic mode applications and specific chemical sensing.

Main Methods:

• Utilized the cleaved end of an optical fiber as a substrate for sensor fabrication.
• Employed photo-initiated free-radical polymerization for a single-step, through-fiber fabrication of polymer beams.
• Functionalized polymer cantilevers using molecularly imprinted polymers for targeted analyte detection.

Main Results:

• Successfully fabricated high-aspect-ratio polymer cantilever sensors directly on optical fibers in a single step.
• Demonstrated the dynamic mode operation of the fabricated cantilevers in air.
• Validated the sensor's capability for humidity and specific chemical sensing applications.

Conclusions:

• The developed through-fiber fabrication method offers an efficient route to creating polymer cantilever sensors on optical fibers.
• These fiber optic sensors show significant potential for sensitive and selective detection of environmental analytes.
• This approach overcomes microfabrication challenges, paving the way for new integrated optical sensing devices.