Graphene-Based Flexible Thermal Sensor and Thermopile Approach for Enhancing Thermometry Sensitivity in Next-Generation Wearables

In this letter, a novel graphene-based thermal sensor was prepared by coating polyvinylidene fluoride or polyvinylidene difluoride/graphene nanoplatelets (GNPs) on commercial textiles. The obtained graphene-coated textile functioned as a thermocouple and exhibited exceptional electrical and thermal characteristics, along with flexibility, chemical stability, and corrosion resistance. The sensor's sensitivity was enhanced by combining two thermocouples based on the thermopile principle, resulting in an open-circuit voltage (OCV) of 2.5 mV at a temperature differential of 32 °C, enabling reliable temperature monitoring for a variety of applications. Furthermore, the produced graphene-based thermal sensors demonstrated a fast response time of 1.5 s, making them more durable and adaptable compared to conventional alternatives. This graphene-based thermal sensor represents a significant advancement in temperature measurement technology, offering enhanced precision and reliability in industrial and research settings.