Polycrystalline graphene curved by grain boundary for high performance nanoresonators

The grain boundaries (GBs) in polycrystalline graphene (PG) lead to distinctive mechanical and electronic properties relative to their single-crystalline counterparts. In particular, local buckling occurs in the presence of GBs, resulting in arched structures promising for high frequency nanoresonators with raised quality (Q) factor. In this paper such arched PG structures were studied by using software Avogadro and their fundamental vibrations were simulated based on a molecular structure model. The frequency and Q factor of the PG nanoresonators were found to be largely increased due to the GB-induced buckling. The major factors controlling such GB effects were also captured, including the inflection angle of the arched PG, the crystal orientation of its GB and the constraints on its boundaries. The study suggests that the presence of GB may lead to a novel strategy to enhance the structure stiffness of graphene for their potential applications in high performance nanoresonators and nanosensors.