Novel Nickel Oxide/Graphene Composite Sensor: A Low‐Temperature Approach to Flexible Temperature Sensing

Abstract Accurate temperature monitoring is crucial in sectors such as food safety, healthcare, and environmental management, where precise monitoring is crucial. While integrated circuit (IC) based sensors are known for their high sensitivity, they suffer from limitations, including high production costs, complex fabrication, and poor performance in humid environments. This study developed a novel Nickel Oxide (NiO)‐based temperature sensor using the doctor blade technique, incorporating a nanocomposite of polystyrene (PS) and graphene to enhance flexibility, stability, and conductivity. The sensor demonstrates a rapid response time of ≈30 s and high sensitivity with a B‐value of 2354 K. Long‐term stability tests show minimal drift and consistent performance over 50 days, with a low coefficient of variation of 1.19%. The sensor also exhibits robust performance under varying relative humidity conditions (RH≈10%–65%) and mechanical strain, maintaining functionality after repeated 80 bending cycles at a bending radius of 2.1 cm. The results indicate that this NiO‐based sensor is a promising candidate for applications requiring reliable and flexible temperature monitoring, providing a cost‐effective and scalable alternative to traditional IC‐based sensors.