Myelin Sheath-Inspired Hydrogel Electrode for Artificial Skin and Physiological Monitoring

作者：Chencong Liu, Yuanyuan Wang, Shitao Shi, Yubo Zheng, Zewei Ye, Jiaqi Liao, Qingfeng Sun, Baokang Dang, Xiaoping Shen · 发表于：ACS Nano · 年份：2024 · DOI：10.1021/acsnano.4c07677 · 被引用次数：50 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Conducting polymers and applications、Neuroscience and Neural Engineering

Significant advancements in hydrogel-based epidermal electrodes have been made in recent years. However, inherent limitations, such as adaptability, adhesion, and conductivity, have presented challenges, thereby limiting the sensitivity, signal-to-noise ratio (SNR), and stability of the physiological-electrode interface. In this study, we propose the concept of myelin sheath-inspired hydrogel epidermal electronics by incorporating numerous interpenetrating core-sheath-structured conductive nanofibers within a physically cross-linked polyelectrolyte network. Poly(3,4-ethylenedioxythiophene)-coated sulfonated cellulose nanofibers (PEDOT:SCNFs) are synthesized through a simple solvent-catalyzed sulfonation process, followed by oxidative self-polymerization and ionic liquid (IL) shielding steps, achieving a low electrochemical impedance of 42 Ω. The physical associations within the composite hydrogel network include complexation, electrostatic forces, hydrogen bonding, π-π stacking, hydrophobic interaction, and weak entanglements. These properties confer the hydrogel with high stretchability (770%), superconformability, self-adhesion (28 kPa on pigskin), and self-healing capabilities. By simulating the saltatory propagation effect of the nodes of Ranvier in the nervous system, the biomimetic hydrogel establishes high-fidelity epidermal electronic interfaces, offering benefits such as low interfacial contact impedance, significantly increased SNR (30 dB), as well as large-scale se...