Self-healing and adhesive eutectogel with skin-like softness and toughness for durable ionic skins

With the rapid advancement of wearable ionic skin, there is an increasing demand for multifunctional ionic-conductive soft materials capable of maintaining stable contact with human skin while withstanding deformation, damage, and fluctuating environmental conditions. However, achieving skin-like softness and toughness, robust adhesion, and rapid self-healing capacity in one material remains a significant challenge, as enhancing mechanical robustness often compromises the critical network dynamics necessary for interfacial adaptability and self-healing. Here, we introduce a physically cross-linked double-network eutectogel, composed of interpenetrating gelatin and poly (2-hydroxyethyl acrylate) (PHEA) networks, using choline chloride:glycerol (ChCl:Gly) as the dispersion medium. Due to abundant noncovalent interactions among gelatin chains, PHEA chains, and ChCl:Gly, the resulting eutectogel demonstrates skin-like softness (elastic modulus ≈12 kPa), high stretchability (>630%), and notable toughness (194 kJ/m 3 ). Notably, our eutectogel also exhibits excellent environmental stability, rapid self-healing ability within 5 mins and strong interfacial adhesion, ensuring robust and conformal contact with human skins with long-term stability and extended service life. Therefore, this eutectogel can function as a reliable ionic skin, capable of achieving high-precision strain and temperature sensing, as well as electrophysiological signal acquisition (ECG and EMG), showing great potential applications for multimodal ionic skins in complex environments.