Improving bending rigidity of graphene nanoribbons by twisting

Abstract

The idea of switching from rigid silicon electronic devices to compact foldable devices have been actively developing in recent years. It is a well established fact that introduction of twist deformation can considerably modify physical and mechanical properties of 2D materials. Considering the fact that the loss of the flat shape can happen easily under in-plane compression due to low bending stiffness of those materials, it is important to look for the methods to increase their buckling stability. Our numerical analysis indicates that the resistance of the twisted nanoribbon to compressive load can be higher than that of the flat one. By twisting, it is possible to increase the bending stiffness of the nanoribbon and it is shown that the optimal twist angle is close to π radian, at which the second moment of nanoribbon cross section area in the middle part of the nanoribbon is close to maximal value. Such twisted configuration creates a substantially greater resistance to axial compression than the flat nanoribbon. Our study contributes to understanding of mechanical behavior of thin films subjected to torsion and can assist in promotion of design of materials for flexible electronics with predictable behavior.