Development of a Highly Sensitive and Stable Flexible Temperature Sensor Based on All‐Inorganic Mn–Co–Ni–O Thin Films

Abstract Despite the fact that flexible temperature sensors, which can be mechanically deformed, are used for the fabrication of next‐generation smart electronics over the past few years, the improvement in their sensitivity and stability remains a major challenge. Along these lines, in this work, an all‐inorganic flexible temperature sensor consisting of MnCoNiO (MCNO) spinel structural ceramics film and a flexible 40 µm‐thick mica substrate is fabricated. By precisely controlling the production process, the pure spinel phase MCNO/mica films with low defect density can be obtained. In addition, the activation energy of the proposed flexible ceramic temperature sensor film remains stable in the natural bending state and at radii of curvature of 10, 15, and 20 mm, respectively, accordingly, B 25/50 is relatively stable around the range of 3450–3550 K. Meanwhile, its sensitivity temperature coefficient of resistance value reaches −3.9% °C −1 . More specifically, Δ B 25/50 is less than 1.83%, 1.57%, and 1.32% after thermal shock, application of the bending cycle, and vibration, respectively. The superior performance of this all‐inorganic ceramic film is due to the excellent bonding between the film and the substrate. This work provides an alternative approach to exploit the development of the next‐generation high‐sensitivity flexible electronic devices.