Fabrication of a Self-Healing and Highly Adhesive Ionic Skin with CNC-Reinforced Dual Conductive Network for Human Motion Monitoring and Program Control

Ionic skins are promising for flexible electronics and health monitoring due to their flexibility, potential for safe skin contact, and stimulus responsiveness. However, traditional hydrogel-based ionic skins suffer from poor environmental stability and limited functionality, restricting their long-term reliability. Inspired by the hierarchical structure of human skin, we report a biomimetic ionic skin with an ion-electron dual conductive network reinforced by cellulose nanocrystals (CNC). The material is fabricated via one-pot polymerization of lipoic acid, incorporating [Bmim]Cl ionic liquid, silver nanowires (AgNWs), and CNC. The resulting ionogel exhibits well-balanced properties: high stretchability (565%), adequate tensile strength (115 kPa), rapid self-healing (90% recovery after 12 h at 60 °C), and strong adhesion to various surfaces (930 J·m–2 on copper). The sensing mechanism relies on synergy between ionic conduction and contact-separation of the AgNW network, enabling high sensitivity (GF = 5.8), fast response (190 ms), broad strain range (0–565%), and excellent cycling stability. The sensor accurately monitors diverse human motions (from facial expressions to joint movements) and enables finger-controlled music software and real-time robotic hand manipulation. This work provides a new strategy for developing highly stable, multifunctional ionic skins.