Carbon nanotubes for mechanical applications

Nanoscience has gained significant attraction recently as they have applications in numerous branches of technologies. Carbon nanotubes (CNTs) are tube-shaped materials and produced from the rolled-up graphene sheets, with nanometer-scale diameters and several micrometers or even millimeters in length. From a chemical point of view, CNTs are connected by sp2 bonds, an exceptionally strong molecular interaction form. There are several structures of CNTs, differing in layernumbers, helicity type, thickness, and length. In general, CNTs can be categorized as single-wall Nanotubes (SWNTs) and multi-wall Nanotubes (MWNTs). CNTs as one-dimensional materials possess exceptional mechanical characteristics, including high tensile strength as well as Young's modulus, putting them among the strongest materials in the world. Owing to their unique mechanical characteristics, together with the high aspect ratio, carbon nanotubes have gained many attractions in several mechanical applications including actuators, sensors, structural reinforcement, and fabrication of blades of wind turbines. This chapter provides a review of the mechanical properties and applications of CNTs. Firstly, CNTs and their exceptional mechanical characteristics, which make them promising materials to be applied in several mechanical applications, are discussed. It is followed by explanations about CNT-based nanocomposites, and finally, the main applications of CNTs that arise from their unique mechanical properties are discussed.