<p>Fiber-based wearable sensors have garnered significant interest in next-generation wearable electronics, owing to their remarkable tensile performance and braidability. Nevertheless, achieving multifunctionality and wearer comfort in such sensors remains a challenge. Here, inspired by the unique structure of polar bear fur, we developed a biomimetic fiber featuring a hollow porous architecture that enables continuous production. This innovative fiber serves as a multifunctional platform, integrating capabilities in thermal management, energy harvesting, and strain sensing. Leveraging the hollow and porous structure, the biomimetic fiber-based textiles exhibit excellent thermal insulation performance, maintaining temperature differentials of 31.8 °C and 57.4 °C under ambient temperatures of 80 °C and 120 °C, respectively. The single-electrode triboelectric nanogenerator assembled with the biomimetic fibers exhibits high electrical output performance and good output stability. Moreover, the fiber-based strain sensor achieves a ultralow detection limit (0.01%), a ultra-wide sensing range (628%), and a high sensitivity (GF = 90874 at a strain range of 582%–628%), enableing real-time human motion monitoring and precise control of robotic arm movements. When integrated with machine learning algorithms, it also proves effective in collecting biological signals and recognizing multiple hand gestures, showing great potential for future intelligent gesture-based interaction systems.</p> Graphical abstract <p></p>