Simultaneous Detection of Two Chemicals Using a TE₂₀-Mode Substrate-Integrated Waveguide Resonator

Area of Science:

• Microwave Engineering
• Chemical Sensing
• Materials Science

Background:

• Conventional microwave resonators are limited to single-analyte detection.
• Developing multichannel sensors is crucial for complex chemical analysis.

Purpose of the Study:

• To develop a novel substrate-integrated waveguide (SIW) resonator for simultaneous detection of multiple analytes.
• To enhance the sensitivity and performance of microwave chemical sensors.

Main Methods:

• Utilized a TE20-mode SIW resonator with two distinct high-field regions.
• Integrated two microfluidic channels made of polydimethylsiloxane (PDMS) to perturb electric fields.
• Tested the sensor with ethanol (E) and deionized water (DI) in various combinations.

Main Results:

• The TE20-mode SIW resonator resonated at 8.26 GHz with a -25 dB return loss.
• Successfully demonstrated simultaneous detection of four chemical combinations: [E, DI], [DI, E], [E, E], and [DI, DI].
• Achieved significant sensitivity enhancements of 7.5%, 216%, and 1170% over previous multichannel sensors.

Conclusions:

• The proposed multichannel microwave resonator sensor effectively detects multiple analytes simultaneously.
• This technology offers a substantial improvement in sensitivity for chemical sensing applications.