All-polymer whispering gallery mode resonators for gas sensing

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Polymeric microdisks are investigated for their potential in gas sensing applications.
• Understanding the relationship between polymer swelling and device sensitivity is crucial for improving gas sensor performance.

Purpose of the Study:

• To evaluate the sensitivity of polymeric microdisks to various vapor-phase compounds.
• To investigate the influence of geometric deformation from polymer swelling on gas sensing sensitivity.
• To explore engineering strategies for enhancing microdisk-based gas sensor performance.

Main Methods:

• Testing the sensitivity of polymeric microdisks to humidity, isopropanol, toluene, limonene, 1-butanol, and pentanoic acid.
• Analyzing the correlation between polymer swelling-induced geometric changes and sensor response.
• Correlating microcavity geometry (undercut-to-radius ratio) with humidity sensitivity.

Main Results:

• Pentanoic acid demonstrated the highest sensitivity (23 pm/ppm) with a limit of detection of approximately 0.6 ppm.
• A clear trend was observed where increased undercut-to-radius ratio enhanced humidity sensitivity.
• The study highlights the significant role of geometry deformation in polymer swelling for gas sensing.

Conclusions:

• Polymeric microdisks exhibit selective sensitivity to specific volatile organic compounds and humidity.
• Geometric engineering of microdisks, particularly the undercut-to-radius ratio, offers a viable pathway to optimize gas sensor sensitivity.
• The findings provide insights for designing next-generation, high-performance polymer-based gas sensors.