Ultra-stable Flexible Thermal Sensing Operating from 20 to 1273 K Enabled by the Directly Grown Mo₂C Patterns on...

Transition metal carbides (TMCs) are promising candidates for applications in flexible sensing electronics due to their high intrinsic conductivity, excellent mechanical strength, and mechanical flexibility. However, it remains a critical challenge to synthesize patterned TMCs films on flexible substrates for direct fabricating flexible sensors with superior mechanical and thermal stability under high-temperature environments. Herein, we report an inkjet printing and hydrogen-assisted thermal reduction approach that enables in situ growth of Mo₂C patterns on flexible mica at 750°C. Thickness of the Mo₂C films can be modulated from 10 to 70 nm, while the electrical resistance ranges from 2 to 0.1 kΩ by tailoring inkjet printing cycles. Owing to the large cohesive energy and high bonding strength between the Mo₂C layer and the substrate, the resultant flexible temperature sensors show remarkable sensing performance from 20 to 1273 K, a high temperature coefficient of resistance of 1.7%/K (in the temperature regime over 1200 K), a low response time of about 26 ms, and a thermal stability at 873 K for 4 h. The proposed approach endows a promising platform to design thermally robust flexible sensors for applications in high-temperature environments.