Scalable and Multifunctional PAN‐MXene Composite Fibers for Thermal Management, Photothermal Conversion, Energy Harvesting, and Sensing for Wearable Applications

Developing multifunctional materials that combine efficient heat conduction, energy harvesting, sensing capability, and flexibility is crucial for next-generation portable and wearable electronics. Here, exploiting the remarkable properties of Ti₃C₂T_x MXene nanosheets, multifunctional polyacrylonitrile (PAN)-MXene nanofibers and yarns are fabricated via a straightforward and scalable electrospinning process. Incorporation of MXenes enhances the thermal conductivity of individual PAN nanofibers, as measured by scanning thermal microscopy, and greatly increases the heat conduction capacity of composite yarns, showing a ∼22°C higher surface temperature recorded by infrared thermography. The composite nanofibers also exhibit strong passive heating capability, rapidly reaching up to 60°C under infrared irradiation. Furthermore, MXenes elevate the tribo-negative character of PAN nanofibers, decreasing their surface potential to -360 mV and yielding a high triboelectric power density of 432.7 mW m^-2, approximately 25% higher than pristine PAN. Moreover, the produced composite yarns demonstrate reliable tactile-sensing performance, detecting forces as low as 0.1 N. Altogether, these flexible and durable PAN-MXene structures provide a promising route toward sustainable and energy-autonomous electronic textiles, offering new opportunities in wearable electronics, soft robotics, and smart sensing systems.