Highly Stretchable, Adhesive, and Mechanical Zwitterionic Nanocomposite Hydrogel Biomimetic Skin

The artificial skin-like stretchable ionic sensor device usually requires a synergistic effect of reliable adhesion between human machine interface, reasonable mechanical strength, and visually displayable transparency. A plant-inspired zwitterionic hydrogel was prepared through rapid UV initiation in the existence of cellulose nanocrystals as physically crosslinker and reinforcing agent. The resulting transparent zwitterionic nanocomposite hydrogel successfully brings the synergistic advantages of robust adhesive strength between diversified substrates such as skins, plastics, glass, and steels with remarkable mechanical properties of a superior stretchability over 1000% strain, a mechanical tensile strength up to 0.61 MPa, and compressive strength up to 7.5 MPa, manifesting in superior ionic transport performance, simultaneously. Furthermore, the zwitterionic nanocomposite hydrogel was fabricated as a wearable compliant stretchable pressure-strain sensor in the modality of the skin-adhesive patch to be sensitive to human motion such as finger touch and speech recognition for personal healthcare of patient sensory rebuilding and physiological data acquisition. It maintains compressive cycling sensibility at diverse pressure during 0.5, 1.0, and 1.5 Hz, respectively. The multifunctional zwitterionic nanocomposite hydrogel could also be assembled into flexible electrical devices such as luminescent display and information transfer between human and robot communication for mechanosensory electronics and artificial intelligence.