Ultrafast\nResponse Polyelectrolyte Humidity Sensor\nfor Respiration Monitoring

Abstract

Respiration monitoring\nis important for evaluating human health.\nHumidity sensing is a promising way to establish a relationship between\nhuman respiration and electrical signal. This work describes polymer\nhumidity sensors with ultrafast response for respiration monitoring.\nThe humidity-sensitive polyelectrolyte is <i>in situ</i> cross-linked on the substrate printed with interdigitated electrodes\nby a thiol–ene click reaction. The polyelectrolyte humidity\nsensor shows rapid water adsorption/desorption ability, excellent\nstability, and repeatability. The sensor with ultrafast response and\nrecovery (0.29/0.47 s) when changing humidity between 33 and 95% shows\ngood application prospects in breath monitoring and touchless sensing.\nDifferent respiration patterns can be distinguished, and the breath\nrate/depth of detection subjects can also be determined by the sensor.\nIn addition, the obtained sensor can sense the skin evaporation in\na noncontact way.