▎ 摘　　要

We demonstrate that graphene, as the thinnest possible solid membrane of only one atomic layer thick, exhibits the maximum asymmetry in tensile versus compressive strain induced mechanical instability. Using continuum mechanics analysis and molecular dynamics simulations, we show that for graphene nanoribbons (sheets) with a typical length (size) of similar to 100 nm, the critical compressive strain for buckling instability is only similar to 10(-4)%, while the critical tensile strain for fracture is similar to 2%, a four orders of magnitude difference. Such a large asymmetry implies that practically, strain engineering of graphene devices is only viable with application of tensile strain but difficult with compressive strain. (C) 2011 American Institute of Physics. [doi:10.1063/1.3666856]