Amphibious Breathable Ionic Skin Enabled by Dynamically Interlocked Star-Shaped Ionic Liquid Telomers.

Epidermal ionic skins act as promising adaptable interfaces for bioelectronics, but they often struggle to simultaneously maintain softness, breathability, adhesion, and conductivity across both dry and aquatic environments. Here, we introduce an amphibious ionic skin engineered by integrating a hydrophobic star-shaped ionic liquid telomer as a bulky solvent within an amphiphilic linear poly(ionic liquid) network. The viscous four-arm telomers are dynamically interlocked within the entangled matrix, facilitating robust water-resistant self-adhesion and self-compliance. Meanwhile, the amphiphilic network provides efficient water-permeable channels, ensuring superior moisture breathability in ambient conditions. Compared to conventional small-molecule-based ionic gels, our ionic skin exhibits high underwater stability due to the restricted leaching of the bulky telomeric species. When fabricated into ultrathin film electrodes, the material enables the acquisition of high-fidelity electrophysiological signals in diverse environments, ranging from dry skin to fully submerged states. This topological network design provides a new strategy for developing environment-adaptive skin-like iontronic devices.