Highly Stretchable Sponge-Structured Adhesive Gel with a Conductive Nanoscaffold for Motion Recording

Adhesive gels that combine high stretchability, conductivity, and biocompatibility are attractive for use in wearable electronics. However, integrating functional nanomaterials and reinforcing moieties coherently into deformable gels remains challenging. Here, we report a sponge-structured adhesive gel formed by embedding an interfacially engineered nanoscaffold within semi-interpenetrating polymer networks. The nanoscaffold, created by coating carbon nanotubes with polydopamine and silver nanoparticles, improves dispersion stability, promotes dynamic bonding with polymer chains, and triggers in-situ polymerization of a secondary nanoscale network. The spongelike structure enables stress redistribution, continuous electron transport, and robust cohesion under large and repeated deformation. The gel exhibits high stretchability (∼3600%), reliable conductivity, and 14 KPa adhesion on pig skin with good biocompatibility, allowing sensitive and stable strain recording from subtle finger motions to complex joint movements over 3 h. This work highlights interfacial molecular engineering as an effective strategy to couple molecular interactions with structural integration for multifunctional gels in wearable electronics.