Elastic and Plastic Deformation of Carbon Nanotubes

Abstract

Carbon nanotubes (CNTs) consist of a graphene sheet (two-dimensional hexagonal lattices of carbon atoms) rolled up into a cylinder. This nanoscale structure has generated enormous interest in the research field of science and engineering in the last decades because of its excellent mechanical properties. For example, Young's modulus of CNTs is estimated to be on the order of TPa (i.e., several times stiffer than steel) and the tensile strength is as high as tens of GPa. This means that CNTs are the stiffest and strongest materials on earth. On the other hand, CNTs are known to have its remarkable flexibility when subjected to external hydrostatic pressure and bending force. Owing to such mechanical properties, CNTs are regarded as an ideal material for superstrong nano-fiber and thus hold great promise for use as next-generation materials. It has also been broadly accepted that mechanical deformation of a carbon nanotube causes significant changes in its physical and chemical properties. Precise knowledge of its deformation mechanism and available geometry is, therefore, crucial for understanding the precise physics of CNT systems and in developing CNT-based applications. Here we introduce such remarkable elastic and plastic deformation properties of CNTs, as well as recent theoretical and experimental progresses in the field of many excellent CNT researches.