Controllable Fabrication of Large-Area Wrinkled Graphene on a Solution Surface.

It is unavoidable to form wrinkles, which are folds or creases in a material, in graphene, whenever the graphene is prepared by micromechanical exfoliation from graphite or chemical vapor deposition (CVD). However, the controllable formation and structures of graphene with nanoscale wrinkles remains a big challenge. Here, we report a liquid-phase shrink method to controllably fabricate large-area wrinkled graphene (WG). The CVD-prepared graphene self-shrinks into a WG on an ethanol solution surface. By modifying the concentration of the ethanol solution, we can easily and efficiently obtain WG with a uniform distribution of wrinkles with different heights. The WG shows high stretchability and can withstand more than 100% tensile strain and up to 720° twist. Furthermore, electromechanical response sensors based on double-layer stacking of WG show ultrahigh sensitivity. This simple, effective, and environmentally friendly liquid-phase shrink method will pave a way for the controllable formation of WG, which is an ideal candidate for application in highly stretchable and highly sensitive electronic devices.