Nanotechnology has experienced a rapid growth in the past decade, mostly because of the rapid advances in nano-fabrication techniques employed to fabricate the nanodevices. Nano-fabrication can be divided into two categories: the first is the so-called “bottom up” approach, in which nano-structures are created either by chemical synthesis of nano-wires, nanotubes and nano-particles, or by self-assembly of nano-objects or thin layers to form quasi-periodic arrays or phase separation patterns