Surface‐Activated Phenol‐Urethane Elastomer Enabling Tough, Adhesive, and Conductive Interfaces for Stretchable Hybrid Electronics

Interfacial mismatch between soft substrates and rigid components fundamentally limits the reliability of stretchable hybrid electronics (SHEs), especially when attempting to simultaneously achieve high bulk strength and strong interfacial adhesion. Here, we introduce a surface activation strategy based on dynamic phenol-urethane bond exchange to enable self-adhesive and conductive stretchable conductors, allowing rigid electronic devices to be directly attached to the substrate in a plug-and-play manner. A dynamic bisphenol polyurethane elastomer (BPU) was designed to unify high intrinsic strength with tunable dynamic activity by programming phenol-urethane bonds, resulting in broadly tunable mechanical properties, with tensile strength ranging from 15 to 50 MPa and elongation from 395% to 757%. After 45 min of ethanol-vapor activation, the BPU surface achieved a peeling strength of 10.5 N/cm while maintaining high mechanical strength (26.6 MPa). A semi-embedded conductive network was constructed by thermally induced reorganization of Ag nanowires (Ag NWs), yielding stretchable conductors with low sheet resistance (11 Ω/sq), strong adhesion (7.75 N/cm), and high stretchability (≈270%). The prepared SHEs sustain up to 250% strain and retain stable conductivity after 4000 cycles under 30% strain, demonstrating the effectiveness of surface activation in strengthening soft/hard interfaces.