Ultrafast Response Polyelectrolyte Humidity Sensor for Respiration Monitoring

• Published in: ACS applied materials & interfaces Vol. 11; no. 6; pp. 6483 - 6490
• Main Authors: Dai, Jianxun, Zhao, Hongran, Lin, Xiuzhu, Liu, Sen, Liu, Yunshi, Liu, Xiupeng, Fei, Teng, Zhang, Tong
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 13.02.2019
• Subjects: adsorption; crosslinking; desorption; electrodes; electrolytes; evaporation; human health; humans; humidity; monitoring; polymers; polyelectrolyte humidity sensors; in situ preparation; ultrafast response; breath monitoring; click reaction
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.8b18904

Respiration monitoring is important for evaluating human health. Humidity sensing is a promising way to establish a relationship between human respiration and electrical signal. This work describes polymer humidity sensors with ultrafast response for respiration monitoring. The humidity-sensitive polyelectrolyte is in situ cross-linked on the substrate printed with interdigitated electrodes by a thiol–ene click reaction. The polyelectrolyte humidity sensor shows rapid water adsorption/desorption ability, excellent stability, and repeatability. The sensor with ultrafast response and recovery (0.29/0.47 s) when changing humidity between 33 and 95% shows good application prospects in breath monitoring and touchless sensing. Different respiration patterns can be distinguished, and the breath rate/depth of detection subjects can also be determined by the sensor. In addition, the obtained sensor can sense the skin evaporation in a noncontact way.