Nanowires A nanowire is a nanostructure and a solid, cylindrical wire with a diameter usually less than 100 nm or structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length where quantum mechanical effects are important. Types Many different types of nanowires exist, including metallic (e.g., Ni, Pt, Au), semi conducting (e.g., Si, InP, GaN, etc.), and insulating (e.g., SiO2, TiO2). Molecular nanowires are composed of repeating molecular units either organic (e.g. DNA) or inorganic (e.g. Mo6S9-xIx). The nanowires could be used to link tiny components into extremely small circuits. Classification Generally, nanowires are classified according to their structures: a) crystalline, those with structured alignments of polymer chains, b) polycrystalline, those with repeating chemical units for molecules, and c) nearly amorphous, those with random alignment of polymer chains. The varying shape is because the nanowire is only periodic alon