Modulus‐Tailorable, Stretchable, and Biocompatible Carbonene Fiber for Adaptive Neural Electrode

Abstract The extraneural electrodes that cling to the nerve show great advantages in decreasing the damage of nerves, as compared to the intraneural electrodes. The grand challenge for the extraneural electrode is the instability of its electrode–nerve interface during nerve movement. In the proposed research, an adaptive, stretchable, and biocompatible carbonene extraneural electrode, which integrates rigid 2D defective graphene nanosheets on the soft carbon nanotube (CNT) fiber, is designed. The rigid nanosheets and the soft nanotubes are dominated by sp 2 nanocarbon, which is defined as carbonene. Benefiting from the soft and robust nature of the CNT fiber, the hybrid carbonene electrodes can be facile‐tailored into various complex shapes with a wide range of modulus (0.5–600 kPa), which plays a significant role in mechanical match of the modulus with that of the nerve. Moreover, the hybrid carbonene fiber exhibits excellent electrical conductivity (3.3 × 10 5 S m −1 ) and novel biocompatibility. As a result, the carbonene electrode shows a preferable performance compared to the traditional metal electrode, whose peak‐to‐peak action potential is 310% higher than the commercial Pt electrode. Overall, this work proposes a novel strategy for assembling the facile‐tailorable and biocompatible carbonene electrode, which can open an avenue for designing the next‐generation neural electrode.