Harmonizing the Mechanical‐Electrical Property Trade‐Off in Aramid Triboelectric Fiber Enabled by In Situ Tessellation

Polymeric electronic fibers are essential for the seamless integration of intelligent wearable systems. However, it remains challenging to simultaneously enhance the load capacity and conductivity of electronic fibers at the micrometer scale. Herein, this study proposes an in situ tessellation strategy that triggers the confined polymerization of pyrrole monomers within an aramid nanofiber crosslinked network, resulting in the construction of high‐strength and electrically conductive aramid triboelectric fibers. Polypyrrole molecules are tessellated into highly oriented aramid nanofibers, where multilevel interfacial hydrogen bonding integrates the intrinsic mechanical strength of the fibers with the superior electrical properties of polypyrrole. Benefiting from this interfacial hydrogen‐bond reinforcement, the aramid triboelectric fibers exhibit an exceptional load‐bearing capacity exceeding 166 667 times their own weight. The tessellated polypyrrole endows the fibers with excellent electrical conductivity (1632 S/m), enabling rapid Joule heating that raises the aramid triboelectric fibers temperature to 74°C within 65 s. The aramid triboelectric fiber is integrated with a relay to form an interactive switch for a temperature regulation system. Furthermore, when paired with a Bluetooth module, the fiber enables real‑time monitoring and wireless transmission of human motion status, providing critical support and data protection for exercise in extremely cold environments.