Graphene folds by femtosecond laser ablation

We report the production of graphene folds induced by femtosecond laser ablation. A single laser pulse irradiation on graphene produced an ablated spot featuring in its proximity circumferentially periodic graphene folds. The graphene fold structure was constructed through folding of a single layer graphene segment. We investigated the laser fluence effect on the graphene fold structure. We also performed ablation on suspended graphene and verified that interaction with the underlying substrate is required for the formation of graphene folds. We expect this one-step folding method may provide a controlled process to explore properties of graphene folds. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4724213]