石墨烯剪纸的大变形拉伸力学行为研究

Investigation on the large tensile deformation and mechanical behaviors of graphene kirigami

将传统宏观剪纸技术应用于纳观尺度,通过引入圆角矩形切口图案构建了石墨烯剪纸.采用分子动力学方法研究了单层与双层石墨烯剪纸的大变形拉伸力学行为和变形破坏机制,并系统地研究了关于切口图案的3个无量纲几何参数对单层石墨烯剪纸的力学性能和变形破坏机制的影响规律.研究发现,通过引入规则切口,可以有效地大幅度提高石墨烯的延展性,其断裂应变可达到完美石墨烯的5—6倍.通过控制3个几何参数,可以有效地调控石墨烯的延展性和力学行为.研究结果表明,古老的剪纸技术为提高二维纳米材料延展性、实现光电纳米器件可延展柔性化提供了一种新的解决方案.

One of the main challenges in developing future stretchable nanoelectronics is the mismatch between the hard inorganic semiconductor materials and the ductility requirements in the applications.This paper shows how the kirigami architectural approach,inspired by the ancient Japanese art of cutting and folding paper applied on macroscale,might be an effective strategy to overcome this mismatch on nanoscale.In this work,the tensile large deformation and mechanical behaviors of armchair and zigzag graphene kirigami with rectangles and half circles cutting patterns are investigated based on classical molecular dynamics simulations.The effects of three non-dimensional geometric parameters that control the cutting patterns on the mechanics and ductility of graphene kirigami are also studied systematically.The results indicate that the enhancement in fracture strain can reach more than five times the fracture strain of pristine graphene.The defined three parameters can be adjusted to tailor or manipulate the ductility and mechanical behaviors of graphene.These results suggest that the kirigami architectural approach may be a suitable technique to design superductile two-dimensional nanomaterials and potentially expand their applications to other strain-engineered nanodevices and nanoelectronics.