Polymer coated silicon microring device for the detection of sub-ppm volatile organic compounds

Polymer coated silicon microring device for the detection of sub-ppm volatile organic compounds
Title:
Polymer coated silicon microring device for the detection of sub-ppm volatile organic compounds
Other Titles:
Sensors and Actuators B: Chemical
Keywords:
Publication Date:
31 October 2017
Citation:
Dongliang Fu, Jaehoon Chung, Qing Liu, Riazul Raziq, Jack Sheng Kee, Mi Kyoung Park, Suresh Valiyaveettil, Pyng Lee, Polymer coated silicon microring device for the detection of sub-ppm volatile organic compounds, Sensors and Actuators B: Chemical, Volume 257, 2018, Pages 136-142, ISSN 0925-4005, https://doi.org/10.1016/j.snb.2017.10.166.
Abstract:
We present a polymer-coated silicon microring resonator to detect volatile organic compounds (VOC) gases. Absorption of VOC gases into the polymer alters the refractive index around the microring, which enables quantification of absorbed gases as a resonance wavelength shift in the resonator. Two different polymers, hyperbranched polyesteramid and poly(2-vinyl pyridine), are tested as the absorption layers on the highly sensitive (80 nm/RIU and 10,000 Q-factor) silicon microring resonator. The sensing responses to VOC gases are characterized by flowing four different gases: styrene, acetone, toluene, and isoprene, in a wide range of concentration (sub-ppm to 100 ppm range). The hyperbranched polyesteramid coated sensor shows the highest sensitivity to styrene. Similarly, Poly(2-vinyl pyridine) coated device exhibits sensitive responses to styrene and acetone. From experiments with a wide range of gas concentrations, we observe that the sensors have two distinguished characteristics; linear and non-linear response with respect to gas concentration. To account for it, a dual mode sensing mechanism is proposed; Langmuir mode (doping effect) in the low concentration (<5 ppm) and Henry mode (swelling effect) for higher concentration of gases. With the developed sensors, we have achieved successful detection of styrene and acetone as low as 100 ppb.
License type:
PublisherCopyrights
Funding Info:
Description:
ISSN:
0925-4005
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