The field of carbon nanotubes has advanced quickly and broadly on many fronts during the past decade. Controlled fabrication of carbon nanotubes of uniform diameter, length, and spacing is now feasible. Real and perceived potential applications in electronics, sensing, molecular biology, actuation, composite materials, and energy storage have been demonstrated. This chapter introduces some of these advances and some of the fundamental properties of the carbon nanotubes, discusses the underlying physics of new effects and phenomena observed or anticipated, and describes the controllable fabrication processes of new forms of nanotubes, as well as some interesting and relatively new and unconventional directions of potential applications.

10.1 Introduction

Soon after the landmark report on the observation of carbon nanotubes by lijima in 1991 [1], numerous findings and assessments about nanotube properties and potential applications were put forward that established the carbon nanotube as an idea base material for future technologies in a broad range of applications. As a new material, carbon nanotubes are indeed remarkable by all accounts. They can be semiconducting with a bandgap ranging from approximately 20 meV to 2 eV, or be metallic, and capable of sustaining current densities that are hundreds of times greater than those of a bulk metal [2]. They come in lengths ranging from a few nanometers to a few hundred micrometers, with diameters of less than a nanometer up to a couple hundreds of nanometers. They can even take the form of a three-port transistor-like structure [3] and can be...