Anisotropic bending of graphene with grain boundaries: Insights from tight-binding simulations

Abstract

Graphene grain boundaries (GBs) are associated with distinct mechanical and physical properties. To utilize these properties requires comprehensive investigation of the GB-controlled nanomechanics. Currently, there is short of fundamental understanding of the out-of-plane bending of graphene in the presence of GBs and the mechanical properties of related curved structures. Here with density functional theory-based tight-binding objective molecular simulations, we revealed anisotropic nonlinear bending of graphene with tilt GBs. The anisotropy and nonlinearity are caused by the dislocation cores which display out-of-plane protrusions. In addition, we investigated the GB-controlled elastic responses of curved graphene configurations, and established the coupling between the elastic modulus and local curvature near the GBs. Our findings serve as useful references for 3D graphene structure design utilizing GBs and can be generalized to other 2D materials.