Subjecting a graphene monolayer to tension and compression.

Themechanical behaviorof grapheneflakesunderboth tension and compression is examined using a cantilever-beam arrangement. Twodifferent sets of samples are employed.One consists of flakes just supported on a plastic bar. The other consists of flakesembeddedwithin theplastic substrate.Bymonitoring the shift of the 2DRaman linewith strain, information on the stress transfer efficiency as a function of stress sign and monolayer support are obtained. In tension, the embedded flake seems to sustain strains up to 1.3%, whereas in compression there is an indication of flake buckling at about 0.7% strain. The retainment of such a high critical buckling strain confirms the relative high flexural rigidity of the embedded monolayer. The mechanical strength and stiffness of crystalline materials are normally governed by the strength and stiffness