Nanomechanical Unfolding of Self-Folded Graphene on Flat Substrate

We report the nanomechanical unfolding of individual self-folded graphene flakes on a flat substrate by using atomic force microscopy techniques. The nanomechanical measurements and molecular dynamics simulations reveal the detailed unfolding process that turns a z-shaped self-folded graphene segment into a flat membrane. A reversible sliding phenomenon in the adhered graphene region during the unfolding process is observed. The findings are useful to better understand the reversible folding properties of graphene and in pursuit of reversible and morphing graphene origami.