Non-Woven Paper-Based Facile Ultra-Fast Response Capacitive Sensor for Respiration Monitoring

The demand of flexible sensor for humidity and respiration monitoring is increasing day by day because of its low-cost and portability. Herein, we presented a facile fabricated, ultra-sensitive and fast responsive parallel plate (PP) capacitive-based humidity sensor for respiration monitoring. The material used for sensor fabrication are copper tape as electrode, Polyethylene terephthalate (PET) as the flexible substrate, and. Nonwoven-paper as a sensing layer. The sensor shows a rapid absorption and desorption behavior due to the use of sensing layer as a nonwoven-paper. The sensor response was examined for percentage relative humidity from 40%-100% RH and a response is observed as 68-1110pF. The sensor is highly sensitive and it's shows a fast response/recovery time of 1s/1.5s. The sensor was also analyzed for different respiration forms with slow, fast, normal, and deep breathing; also, a different response is observed for mouth and nasal breathing. Due to its low cost, stability, sensitivity, repeatability, and eco-friendly behaviors the sensor is found to be the most promising candidate for respiration monitoring in medical fields.