A Flexible Temperature Sensor with Ultrafast Response Speed and High Stability Achieved by Improving Substrate Thermal Conductivity and Radiative Cooling

Abstract Flexible temperature sensors have great potential for application in human‐computer interaction and disaster prevention systems. However, the slow response rate makes it difficult to quickly respond to human health conditions, and its stability is difficult to maintain in various environments, limiting its range of use. In this study, a fast‐response, highly stable temperature sensor based on a breathable nanofiber platform is prepared. The response speed (0.32 s) is improved by introducing oriented boron nitride nanosheets (BNNS) with high thermal conductivity into TPU (thermoplastic polyurethane elastomer) nanofibers; the high sensitivity (0.077 °C ⁻¹ ) is realized by adding polyaniline (PANI) to graphene (G). High stability and signal‐to‐noise ratio (SNR) are achieved by covering the sensing layer with the TPU/silica (SiO ₂ ) nanofiber and using the direct printing preparation method. B Besides, the TPU/SiO ₂ nanofiber, with its high visible light reflectance, and the TPU/BNNS nanofiber enable the sensor to exhibit excellent human thermal management capabilities, lowering body temperature by up to 5 °C in outdoor conditions compared to standard clothing. For application verification, the sensors are used for long‐term temperature monitoring of the human body in various environments, as well as for respiratory and battery temperature monitoring. This study opens a promising path for improving the response speed and reliability of temperature sensors.