Developing a Printed Respiration Rate Sensor for E-textile Applications

Real-time monitoring of the vital signs in everyday life enables early detection of various diseases and disorders that can cause a life-threatening incident. In this paper, a biocompatible strain sensor for real-time monitoring of the human respiration rate is proposed. The sensor consists of a stretchable fabric substrate impregnated with carbon black through drop-casting at ambient conditions. The proposed passive sensor provides a change in electrical resistance from 160 Ω down to 80 Ω against applied tensile strain 0 % to 16 %. Electrical resistance of the sensor decreases due to shrinkage of the conducting yarns and resets to the initial resistance value when released with the help of Polydimethylsiloxane (PDMS) encapsulation elastomeric properties and fabric’s stretchability. The resistance variation phenomenon is exploited for the respiration rate detection application. The sensor is characterized for electrical and mechanical properties. The proposed sensor can be a good candidate for the respiration rate monitoring in E-textile and wearable electronics.