Graphene, as one-atom-thick membrane, is susceptible to morphological instabilities such as wrinkles, crumples and folds, which are attributed to several physical causes, such as the mismatch between its thermal expansion and its host substrate or the relaxation of a pre-strained substrate. A particular pattern encountered in graphene grown via Chemical Vapour Deposition is that of mosaic formation, which results from the imposition of thermo-mechanical stresses upon cooling from high temperatures.

Despite several approaches have been proposed to tailor the morphology of graphene, it has not been possible to create such a complex pattern at room temperature by mechanical loading. In this work, we have managed by means of lateral wrinkling induced by tension and Euler buckling resulting from uniaxial compression upon unloading, to create such mosaic patter in exfoliated graphene. Very interestingly, we have proven that the mosaic pattern can be harnessed as channels for trapping or administering fluids at interstitial space between graphene and its support. Therefore, the formation of mosaic morphology in graphene by mechanical deformation may open a whole dearth of new applications in the area of nano-fluidics but also in photo-electronics and sensor technologies.

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