This edited book brings together 16 state-of-the-art chapters written by different groups covering most areas of CNT research and technology. It will be a valuable reference work and an important addition to the CNT literature, and will appeal to scientists and engineers involved with nanomaterials, nanodevices, and fabrication at the nanoscale level. Chapter 1 deals with the fundamental properties of carbon nanotubes. It discusses details about the bonding between the CNT carbon atoms, structure of single wall carbon nanotubes (SWCNTs), for example, the classification of SWCNTs, electronic structure of SWCNTs starting with that of graphene and advancing to that of CNTs, phonon modes of CNTs starting with the dispersion of modes in graphene to those in CNTs, and optical properties of CNTs involving discussion of selection rules and excitons. Chapter 2 deals in some detail with the synthesis, both laboratory scale and large scale using fluidized bed methods, of CNTs. Some readers, however, may have to consult a few of the comprehensive references given for more details. Chapters 3 and 4 deal with the assembly of nanotubes particularly in the form of polymer nanocomposites and the separation of metallic and semiconducting CNTs, respectively. Chapters 5 discusses electronic applications of SWCNTS—for example, field effect transistors (FETs) and logic circuits, Schottky-contact FETs, ohmic contact FETs, and the performance limit of CNT-based FETs. Other areas considered in Chapter 5 are single electron transistors and circuits, and memory and other electronic devices. Chapter 6 deals with high frequency applications of CNT electronics, Chapter 7 considers the status and trends in bulk and CNT tunneling FETs, and Chapter 8 provides details about transistors based on CNT networks. The latter chapter reviews methods of sorting CNTs by electrophoresis, polymer wrapping, DNA wrapping and selective functionalization, and the use of ultracentrifugation, debundling, and selective removal of metallic tubes to create SWCNT networks. Chapter 9 deals with CNT field emission technology for vacuum electronic device applications with the potential for rapid commercialization. Chapter 10 stands apart from the rest of the book in revisiting the controversial area involving magnetic and electrical properties suggesting ultrahigh temperature superconductivity in nickel particles embedded in multiwalled CNTs. Chapter 11 is focused on a review of work on CNT based biosensors which has sections on the electrochemical properties of CNTs and functionalization of CNTs. Chapter 12 is a review of work on the use of CNT FETs as gas sensors with a section on the methods that can be used to enhance the selectivity of these devices. Chapters 13–15 deal with viscoelastic applications, the fabrication of microscopic to macroscopic CNT fibers, and mechanical applications in resonators and actuators, respectively. The final chapter reviews work on the nonlinear properties of SWCNTs which stem from their estimated ultrahigh third order nonlinearity originating from interband transitions involving the π-electron system of the CNTs.