Breathable, Adhesive, and Biomimetic Skin-Like Super Tattoo.

Electronic tattoo, capable of imperceivably acquiring bio-electrical signals from the body, is broadly applied in healthcare and human-machine interface. Tattoo substrate, the foundation of electronic tattoo, is expected to be mechanically mimetic to skin, adhesive, and breathable, and yet remains highly challenging to achieve. Herein, the study mimics human skin and design a breathable, adhesive, and mechanically skin-like super tattoo substrate based on an ultra-thin film (≈2 µm). Similar to skin, super tattoo demonstrates strain-adaptive stiffening properties with high tear energy (5.4 kJ·m-2) and toughness (1.3 MJ·m-3). Superior to skin, it exhibits high adhesion, ionic conductivity, and permeability. A variety of conductive electrodes can be processed on it, showing the universality toward an ideal platform for electronic tattoo with stable and low contact impedance. Super tattoo-based electrodes can imperceivably and accurately monitor weak electromyography (EMG) of swallowing on the junction, providing effective guidance for rehabilitation training of dysphagia.