A breathable and self-healing deep eutectic conductive and tissue adhesive hydrogel for strain sensor and continuous glucose monitoring.

The development of integrated wearable sensors for concurrent physical and biochemical monitoring is hindered by mechanical mismatch, poor interfacial stability, and low breathability. Herein, we present a thin (100 μm), breathable, self-healing hydrogel (ChACm) with deep eutectic conductivity and tissue adhesion. The hydrogen bonding, catechol/phenol-mediated and hydrophobic association networks enable efficient self-healing (91%) and strong adhesion to wet artificial skin (interfacial toughness: 300 J m-2, adhesive strength: 210 kPa). Its high water vapor transmission rate (WVTR:1980 g·m-2·day-1) and ionic conductivity (0.58 S m-1) enable its use as a ChACm-based strain sensor. A skin-interfaced glucose monitoring device was fabricated with ChACm as the adhesive layer. Both the strain sensor and the glucose monitoring device maintain low skin-electrode impedance and accurately capture joint movements. Notably, the glucose sensing system, in which ChACm serves a stable, breathable and low-impedance skin interface, exhibits reliable subcutaneous glucose tracking over 14 days, with reproducible signals and durable interfacial contact.