High-sensitive Flexible Temperature Sensor with PEDOT:PSS Composites and PI Substrate for Human Body Monitoring

Flexible temperature sensors have been studied for a long time and their performance has been improving. However, their sensitivity, response and recovery speed, reproducibility, consistency and other properties need to be further optimized and balanced for being better and more widely used in life. In this study, we report a resistive-type temperature sensor that was fabricated using a composite of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate)/ single-wall carbon nanotubes/ reduced graphene oxide (PEDOT:PSS/SWCNTs/rGO) on the polyimide (PI) substrate by rapid vacuum suction filtration and spin-coating method. This sensor exhibits a high thermal sensitivity with -0.33 % ℃ ⁻¹ temperature coefficient of resistance (TCR) between 30 and 45 ℃. Furthermore, it shows fast response and recovery speed and excellent reproducibility. As demonstration, the temperature sensor was applied in monitoring daily life sensations, such as exhaling, finger touching and the temperature change of the body skin surface. The flexible temperature sensor shows great potential in towards various applications, such as electronic skins, robot sensors, human-machine interface, and environmental temperature measurement.