Single-walled carbon nanotubes(SWNTs) have attracted substantial research interest during the past decade, owing to theri unique quasi-one dimentional structure,nanometer size, as well as exceptional electrial, mechanical, optical, thermal and chemical properties. Among those atttibutes, their mechanical and electrical properties are most noticeable.Nanotubes are the among the strongest fibers in the world, with a Young's modulus in the range of 1-2 TPa and fracture sress of -50 GPa, as determined from SWNT bundles as well as arrays of isolated SWNTs.

Depending on their chirality and diameter, SWNTs can behave as either a metallic meterial, i.e a material with zero band gap, or a semiconductor material. Semiconductor SWNTs are envisioned as a very promising material candidate to replace or complement single-crystalline silicon in the next generation high-performance nanoelectronic devices, while metallic SWNTs are proposed SWNTs are proposed to replace copper wire as advanced interconnects in microprocessor chips.

The use of  SWNT films as conductoring materials appears to be a simple idea. However, the overall electrial propeties are intricately dependent on a variety of parameters such as average and adventitious doping frim the amnbient. For conductive films, long and relatively large-diameter SWNTs, which can minimize the role of SWNT-SWNT junctions in transport and the bandgap of SWNCTs, are desired. The conductance can be further improved by doping SWNTs with strong acid/oxygen or by hybridizing with Au nanoparticles.

Combing the conductive SWNT films with semiconducting SWNT films has enabled the realization of flexible transparent transistors using SWNTs for all of the current carrying layers.