Ultracompact MXene V₂C-Improved Temperature Sensor by a Runway-Type Microfiber Knot Resonator

We demonstrate an all-fiber, compact-structure, high-sensing-efficiency temperature sensor using a resonator structure sensor device of a runway type and MXene V₂C. The high-quality functional material MXene V₂C, synthesized by a simple two-step method, has excellent photothermal conversion performance. As-prepared MXene V₂C is integrated into the runway section of a runway-type microfiber knot resonator based on the coupling mechanism between the surface near the field of the fiber and materials. When the temperature variation range is ~25-70 °C, the corresponding transmission light intensity variation is linear, and the maximum normalized sensing efficiency is 2.21 dB/°C/mm. Our work demonstrates that the runway-type structure ensures the compactness of the sensor device and enhances the interaction distance between the material and the microfiber, which provides additional integration strategies for functional material-based sensor devices.