Abstract
Nanotechnology is based on the fact that the properties of materials become a verity of size approaches that of a few hundred or tens of atoms. This technology is reached a point at which the boundaries separating discrete disciplines become blurred, and it is for precisely this reason that nanotechnology is also referred to as a convergent technology. The key application of nanotechnology is the development of processes that control placement of individual atoms to form products of great complexity at extremely small scale. Nanotechnology includes many techniques used to create structures at a size scale below 100 nm. Nanoparticles have proved useful in catalysis. One fundamental characteristic of nanotechnology is that nanodevices self-assemble. Nanotechnology proposes the construction of novel molecular devices possessing extraordinary properties. One of the primary implementation of this technology is the fabrication of low dimensional semiconductor systems. The novel electronic and optical properties of these low dimensional devices are the boon for a variety of future applications. The Metal-Insulator transition is the main criteria for the existence of low dimensional semiconductor systems in the recent observations. Specially designed nanodevices, in the size of bacteria, might be programmed to destroy arterial plaque, or cancer cells, or to repair cellular damage caused by aging, and then be injected into the body.