Multifunctionality and Mechanical Actuation of 2D Materials for Skin-Mimicking Capabilities

Human skin serves as a multifunctional organ with remarkable properties, such as sensation, protection, regulation, and mechanical stretchability. The mimicry of skin's multifunctionalities via various nanomaterials has become an emerging topic. 2D materials have attracted much interest in the field of skin mimicry due to unique physiochemical properties. Herein, recent developments of using various 2D materials to mimic skin's sensing, protecting, and regulating capabilities are summarized. Next, to endow high stretchability to 2D materials, the approaches for fabrication of stretchable bilayer structures by integrating higher dimensional 2D materials onto soft elastomeric substrates are introduced. Accordion-like 2D material structures can elongate with elastomers and undergo programmed folding/unfolding processes to mimic skin's stretchability. That stretchable 2D material devices can achieve effective tactile sensing and protecting capabilities under large deformation is then highlighted. Finally, multiple key directions and existing challenges for future development are discussed.