Ultrapermeable and\nWet-Adhesive Monolayer Porous Film\nfor Stretchable Epidermal Electrode

Abstract

Noninvasive electrophysiological signal monitoring is\nsignificant\nfor health care and scientific research. The simultaneous achievement\nof wet adhesion, stretchability, breathability, and low contact impedance\nis highly recommended in the epidermal electrode but still challenging.\nIn this work, a monolayer porous film electrode with a pore size and\nwall thickness of less than ∼10 μm is fabricated via\nthe breath figure method (BFM) and metal sputtering, and it was subsequently\napplied using epidermal electrophysiological monitoring. The ultrahigh\npermeability is comparable to the naked skin because the through holes\nof the monolayer porous film match well with the pores on human skin.\nThe stretchability of 50% is realized with the combination of Au microcrack\nand the monolayer porous structure. The wet adhesion of 0.17 N/cm\nis established on the chemical bonding between the electrode and the\nepidermis. The contact impedance is comparable with the gold standard\nAg/AgCl gel electrode, especially after sweating. Stable and precise\nelectrophysiological signals are measured. Especially, the perspiration\nresistance of the monolayer porous film outperforms that of the gel\nelectrode. The monolayer porous structure provides a new avenue to\nimprove the breathability of the epidermal electronics.