Mechanical applications of carbon nanotubes

Carbon nanotubes (CNTs) have excellent mechanical and electrical properties. Coupling these two properties could introduce new mechanical devices or improve existing mechanical system/applications at different scales. At microscopic scale, CNTs hold great promise for nanoelectromechanical systems (NEMS), which provide unique motion capabilities and are useful for a range of sensing and detection applications, as well as for studying mechanical motion in quantum limit. At macro scale level, great progress has been made in CNT actuation. Large strain and high stress actuators have been studied based upon CNT electrostatic actuation, CNT electrochemical actuation, and CNT-polymer actuation. Eventually in structural applications, individual CNTs must be effectively aggregated into macroscopic products, so that their excellent properties would be retained at a larger scale and more practicable level. Recent progresses on CNT fibers have demonstrated such a possibility. In this chapter, we will discuss the current status, future research focuses and challenges of several major mechanical applications of CNTs, including CNT nanomechanics, CNT actuators, and high performance CNT fibers.