ABSTRACT
During the past years scientists have achieved signicant successes in nano science and technology. Nanotechnology is a branch of sciences that deals with ne structures and materials with very small dimensions-less than 100 nm. The measurement unit of “nano” has been extracted from the nano-prex, which is a Greek word meaning “extremely ne.” One nano (10-9 m) is the length equivalent to 5 silicon atoms or 10 hydrogen atoms aligned side by side. To introduce a perspective note the following examples: A hydrogen atom is about 0.1 nm; a virus is about 100 nm; the diameter of a red blood cell is 7000 nm; and the diameter of a human hair is 10000 nm.1-3
Nanotechnology is a eld of applied sciences focused on design, production, detection, and employing the nanosize materials, pieces, and equipment. Advances in nanotechnology lead to improvement of tools and equipment as well as their application in human life. Nanoscience is the study of the phenomena emerged by atomic or molecular materials with the size of several nanometers to less than 100 nm. In chemistry this size involves a range of colloids, micelles, polymer molecules, and structures such as very large molecules or dense accumulation of the molecules. In the physics of electrical engineering, nanoscience is strongly related to quantum behavior or electron behavior in structures with nano sizes. In biology and biochemistry, also, interesting cellular components and molecular structures such as DNA, RNA, and intercellular components are considered as nanostructures.4-7
Nanotechnology is applying the sciences in control of the phenomena with molecular dimensions. In this range, materials properties are signicantly different than those of its mass state. These differences are related to design, properties’ detection analysis, structures application, as well as tools and
systems for nano shape and size control. In other words, nanoscience and technology is a study eld including
1. Advances in the methods for producing the materials and surface analysis equipment for producing the materials and structures
2. Understanding the changes in physical and chemical properties in order to materials ning
3. Using these properties for the development of new highly used materials in the equipment
Alive cells are the best examples of machines working at the nano level. The study eld of the nanotechnology major is interconnected to physics, chemistry, materials science, microbiology, biochemistry, and molecular biology. Integration of nanotechnology, biotechnology, and medical engineering is demonstrated in the use of nano-size structures for disease prognosis, dening the gene sequence, and medicine transport.8,9
The main applications of nanotechnology are
• Medicine: drug delivery and tissue engineering • Chemistry and environmental studies: catalysts, ltration • Energy: decrease in energy uses, increasing of the efciency of the
products yielding batteries recycling energy, use of environmentally friendly energy systems
• Information and communications: new semiconductors, new electrical pieces, display monitors with low energy use, quantum computers
• Consumer goods: food production, safety, and packaging, selfcleaner system, bers and textiles, optical equipment, sport facilities
Use of nanotechnology by humans, contrary to the dominant belief, has a long history. There is evidence implying the nanostructured nature of the blue color used by the Mayans. Since then, Romans used these materials for fabrication of cups with live colors; they applied gold for dying these cups. One of these cups was the Lycurgus cup that was made in 4 BC. This cup involves gold and silver particles and reveals various colors once exposed to light. This method was also used in the Middle Ages for making church windows.10,11
Among various scientic elds, biology was the rst that entered this realm. The basic mechanism of biological machines was nanodimensional reactions. Mosquitoes, ants, and ¬ies can be named as examples of natural nanomachines. However, the scientic account of nanotechnology varies
from that explained above. Early investigations on nanoparticles stem from Faraday. In 1811 working on the red colloid of Ag, he found that the red colloid color depends on metallic particles sizes, and the gold and silver found 2000 years ago were actually nanoparticles.
