Tissue-Adhesive Carbon Nanotube Bioelectronics with Intrinsic Stretchability and Mechanical Adaptation

Interfaces for soft bioelectronics must retain conformal and low-noise contact with dynamic and hydrated tissues without causing mechanical mismatches. This study integrates a viscoelastic, self-healing polymer (SHP) with a surface-embedded carbon nanotube (CNT) network and a catechol-modified alginate (Alg-CA) overlayer to enable wet adhesion while preserving polymer-like mechanical properties. Tensile tests across representative strain rates (3.3 and 50% s^-1) indicate that CNT-SHP exhibits a stress-strain response similar to that of pristine SHP. Fracture-energy analysis and rapid stress relaxation show that CNT-SHP follows the energy dissipation characteristics of SHP. The Alg-CA layer improves electrochemical coupling by reducing impedance and increasing charge delivery in vitro, maintaining stability during saline immersion, and supporting wet adhesion on porcine tissues under cyclic loading. Cytotoxicity assays and short-term histology indicate reduced adverse tissue response relative to CNT-SHP without Alg-CA. In vivo, CNT-SHP enables motion-tolerant epicardial electrocardiogram in anesthetized and freely moving rats, maintains multiweek signal quality, supports reliable low-threshold ventricular pacing, and achieves effective sciatic-nerve stimulation. These results demonstrate the potential for stable sensing and stimulation in dynamic and wet tissues.