Graphene helicoid as novel nanospring

Advancement of nanotechnology has greatly accelerated the miniaturization of mechanical or electronic devices/components. This work proposes a new nanoscale spring – a graphene nanoribbon-based helicoid (GH) structure by using large-scale molecular dynamics simulation. It is found that the GH structure not only possesses an extraordinary high tensile deformation capability, but also exhibits unique features not accessible from traditional springs. Specifically, its yield strain increases when its inner radius is enlarged, which can exceed 1000%, and it has three elastic deformation stages including the initial delamination, stable delamination and elastic deformation. Moreover, the failure of the GH is found to be governed by the failure of graphene nanoribbon and the inner edge atoms absorb most of the tensile strain energy. Such fact leads to a constant elastic limit force (corresponding to the yield point) for all GHs. This study has provided a comprehensive understanding of the tensile behaviors of GH, which opens the avenue to design novel nanoscale springs based on 2D nanomaterials.