Fig. 1. Cytoadhesion-inspired quadra-layered hybrids.

a Schematic shows the temporal and spatial differences in the patterns of myoelectric excitation and mechanical contraction in the excitation–contraction coupling process during voluntary muscle contraction. b Schematic of the integrated electromechanical interface (i.e., CoupOn). Right photograph shows one fabricated CoupOn hybrid with the ionotronically conductive zone and the wiring port annotated. The adhesive ionic hydrogel retrieves sEMG signals and the stretchable double metallic nanofilm functions as the resistive strain sensor while transmitting the electrical signals for readouts. The waterproof elastomer mitigates water loss from the ionic hydrogel. Scale bar, 5 mm. c Schematic of strong interlayer adhesion at the integrated electromechancial interface that combines the cytoadhesion-inspired contact splitting and tough interfacial bonding, illustrating dash ciricle in c. Inset, confocal fluorescent images showing an adherent fibroblast labeled with actin microfilaments (red) and focal adhesions (green). Scale bar, 30 µm. d Schematic of the fabrication process of the hybrid CoupOn in five steps.