Coordinated Skin-Electrode Deformation for Switchable Adhesion and Injury-Free Detachment of Epidermal Electrodes.

Human-machine interfaces require thin and conformal epidermal electrodes to detect physiological signals from the human body. A key challenge of such epidermal electrodes is to combine two contradictory but highly desired properties: stable electrode-skin adhesion that enables high-fidelity signal acquisition, and poor adhesion for easy and injury-free removal. Here, we report a soft conducting electrode that well combines the two contradictory properties by tailoring a T-shaped finger and a U-shaped finger and by tuning the stickiness to a mild level. When peeling from the U-finger to the T-finger, the two fingers "pinch" the skin with a large co-deformation between the skin and the electrode for enhanced adhesion. When peeling back, the U-finger is disabled, and the electrode behaves like a non-patterned layer that exhibits poor adhesion for easy detachment. The kirigami-enabled co-deformation of bilayer soft system with a thin surface and thick substrate for switchable adhesion and low interfacial damage might be extended to other human-machine interfaces and beyond.