Hierarchically Engineered Flame-Retardant Triboelectric Yarn Exhibiting Robust Mechanical Performance and Humidity-Boosted Electrical Output for Firefighting Applications

As urbanization progresses and building complexity grows, fire safety gains prominence, driving up demand for intelligent, high-performance fire-fighting gear. This study develops a super-intelligent fireproof yarn (SIFY) with a coaxial structure via hierarchical textile assembly. The middle waterproof and flame-retardant layer and the outer high-strength flame-retardant poly(p-phenylene benzobisoxazole) fibers endow SIFY with top-notch flame-retardant performance (limiting oxygen index of 50.2%), high tensile strength (550.72 MPa), and remarkable wear resistance (over 12 000 rubbing cycles). These properties are currently the best among reported triboelectric yarns. Notably, the innovative design of SIFY ingeniously overcomes the limitations of triboelectric nanogenerators in humid environments. It achieves a remarkable breakthrough where the triboelectric performance increases rather than decreases with rising relative humidity. The unique properties endow SIFY with the capabilities to function as both a power source and a self-powered sensor in intelligent firefighting supplies. It can be utilized in gesture-recognition systems and intelligent firefighting ropes, thereby ensuring safer and more efficient fire-fighting operations for firefighters.