Thermoresponsive dynamic wet-adhesive epidermal interface for motion-robust multiplexed sweat biosensing

Wearable sweat sensors offer noninvasive health monitoring through multiplexed biomarker analysis, delivering real-time diagnostics with continuous operational capability. However, chronic cutaneous interface hydration during prolonged monitoring induces adhesive delamination phenomena that manifest as signal attenuation, which fundamentally limits their clinical reliability. To address this challenge, we developed a thermodynamically adaptive polymer interface combining three functional components: mussel-inspired catechol moieties for moisture-tolerant adhesion, hydrophobic acrylates ensuring mechanical stability, and N-isopropylacrylamide enabling thermal responsiveness. The engineered adhesive demonstrates temperature-dependent interfacial behavior through robust skin attachment maintenance at physiological temperature coupled with significantly weakened adhesion capability below its lower critical solution temperature (LCST, ∼32 °C). Integrated with flexible multielectrode arrays, this dynamic adhesive forms a wet-adhesive multielectrode (WAME) sweat sensor system that enables continuous multiplexed detection of pH, Na⁺, K⁺, and lactate biomarkers during vigorous physical activity. The platform enables wireless real-time metabolite tracking while maintaining motion adaptability and signal stability. This thermoresponsive interface overcomes the adhesion-reliability dichotomy in epidermal electronics, paving the way for clinical translation of long-term wearable biosensing.