Development of Ultrathin, Breathable, Waterproof, and Durable Nanonet‐Supported Ionogel Sensors for Electrophysiological Monitoring

Abstract Ionogel has gained attention as a promising material for flexible electronic skin (e‐skin), due to its exceptional conductivity, compositional stability, and biocompatibility. Nevertheless, establishing a seamless interface between ionogel and human skin remains a significant challenge. This study presents the design and fabrication of a nanonet‐supported ionogel with a thickness of ≈16 µm, marking it the thinnest ionogel reported to date. This ultrathin ionogel exhibits remarkable toughness (5.51 MJ m⁻³), a broad strain range (0–375%), and impressive fatigue resistance, enduring over 3000 cycles. Additionally, it offers excellent water resistance and a high water vapor transmission rate (WVTR), supporting perspiration and enhancing skin breathability. Moreover, the ultrathin ionogel has potential as a carrier in transdermal drug delivery systems (TDDS), highlighting its suitability for biomedical applications. Wearable devices incorporating this ultrathin ionogel facilitate continuous, sensitive, and highly accurate monitoring of physiological signals, positioning it as a promising material for future flexible e‐skin material.