Electronic nano sponge breath ammonia sensors using hygroscopic polymers on vertical channel nano-porous structure
Journal
Journal of Materials Chemistry C
Journal Volume
9
Journal Issue
37
Pages
12938
Date Issued
2021-10-07
Author(s)
Chen, Wei Lun
Chiu, Huang Cheng
Chu, Hsuan
Hsieh, Ju Chun
Chen, Bing Xin
Tian, Ya Chun
Liau, Shuh Kuan
Chan, Ming Jen
Lu, Chia Jung
Meng, Hsin Fei
Horng, Sheng Fu
Zan, Hsiao Wen
Abstract
In this work, insulating hygroscopic polymer thin films have been applied as the vertical-channel sensing layer of extremely sensitive ammonia sensors to detect 5-1000 ppb ammonia. Hygroscopic polymers such as poly(ethylene glycol) (PEG), polyvinyl alcohol (PVA), and poly(acrylic acid) (PAA) serve as good absorbents of ammonia gas. The high-density nano-porous structure covered by a hygroscopic thin film acted like a nano-porous sponge (Nano Sponge) to absorb water, which forms an ionic conduction path in the 300 nm vertical channels. The influences of the polymer functional groups, pH value, relative humidity (RH), and other interfering gas analytes on the sensing performances of theNano Spongesensors have also been investigated. After adding glycerol, the Glycerol/PEGNano Spongesensors exhibited a stable response. Breath detection in a healthy group and a chronic kidney group of patients was examined using the Glycerol/PEGNano Spongesensor in a sensing system with a NaOH tube to control the relative humidity and to absorb the interfering species such as CO and H2S.
Type
journal article