Continuous Spinning of Tough, Robust, Ionic-Conductive, and Stable Fibers for Reliable Signal Transmission

Fiber-shaped ionic conductors are ideal for bioelectronic interfaces due to their structural and functional similarities to biological tissues. However, achieving high mechanical strength, superior conductivity, and long-term environmental stability within a scalable fiber format remains a formidable challenge. Here, we report a design strategy to fabricate tough, robust, ionic-conductive and stable (TRIS) fibers via continuous UV-assisted spinning of a quaternary deep eutectic solvent. The core lies in the synergistic interplay between a highly dynamic hydrogen-bonding supramolecular network and dynamic carboxyl–zirconium coordination complexes. This molecular architecture enables TRIS fibers to simultaneously realize a high Young’s modulus (approximately 8.7 MPa) and excellent ionic conductivity (approximately 0.896 S/m). Furthermore, the fibers exhibit exceptional environmental stability, maintaining stable performance for over 1 year in ambient conditions. As a demonstration, TRIS fibers function as ionic cables that can transmit high-fidelity signals under strain (approximately 50%) and, notably, as artificial nerves to bridge a severed sciatic nerve in rats. The successful restoration of sensory and motor functions in vivo highlights the potential of TRIS fibers as functional neural replacements. This work provides a scalable and robust platform for the development of next-generation, tissue-like implantable bioelectronics.