What is nanotechnology?
Nanotechnology is the study of manipulating matter on a molecular scale. In general this field deals with structures sized between 1 to 100 nanometers (nm) in at least one dimension. . In 1974 Tokyo science university professor Norio Taniguchi defined the term “nanotechnology” as follows; 'Nano-technology' mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or by one molecule."
Nanotechnology is not just a single technical approach. It is a scientific basis for various possible new propositions. For example fields like nanomechanics, nanoelectronics and nanophotonics are new fields which have evolved on the scientific foundation of nanotechnology. As shown above it covers a vast range in science from mechanisms in the conventional physics to absolutely new methods based on self assembly of matter. Nanotechnology deals directly with developing new materials within the nano scale and investigate possibilities and methodologies of controlling matter on the atomic scale.
Unknown history of nanotechnology.
The concept of nanotechnology was first expressed in “There’s plenty of room at the bottom”, a speech given by physicist Richard Feynman at an American physical society meeting at Caltech which was held on 1959. In this speech he described about development of methods to manipulate individual atoms and molecules.
In 1980’s the basic idea of nanotechnology was explored in much more depth by Dr. K. Eric Drexler, who promoted the significance of nano-scale phenomena by the means of speeches and books such as “Engines of Creations: The Coming Era of Nanotechnology” which is considered as the first book on nanotechnology.
Major advancement of the nanotechnology was accompanied by two major moves in the science; the origin of cluster science and the invention of scanning tunneling microscope (STM). This led to the discovery of fullerenes, which are the molecules composed entirely in carbons, in the forms of hollow sphere, ellipsoid or tube, in 1985. After few years carbon nano tubes which is a special type of fullerene was discovered.
Concepts of nanotechnology.
There are two main concepts in nanotechnology; the “bottom-up” concept and the “top-down” concept.
In the “bottom-up” concept, materials are built from molecular components which have the ability of assembling themselves chemically under the principles of molecular recognition and bond formation. DNA nanotechnology and chemical synthesis are based on this approach.
In the “top-down” concept objects in the nano scale are constructed from larger entities. The “top-down” concept doesn’t involve any control of the formation of nano bodies at the atomic level.
In this scenario scaling issues would arise from changing the magnitude of various physical phenomena.
While approaching the nano scale, properties of matter greatly changes from their properties at the macro or micro scale. Therefore at the nano level unique behaviors can be observed in the matter. Nanotechnology is about creating, studying and manipulating these special behaviors in a desired manner. By controlling these unique properties, never imagined tasks could be achieved. For example at the nano scale clay bricks are able to transmit electricity which they are completely unable to do at the macro scale. As a result we will be able to transmit electricity through specially laid paths of nano-bricks inside the walls instead of using metal cables.
Manipulating matter at the nano scale is a main focus in the field of nano science. Because all the future achievements in nanotechnology is based upon those handling methods. Without the proper and adequate control, as everything, nano materials can act in a hazardous way, that they may harm both living and non-living bodies existing. Therefore before approaching the sophisticated creations in this field, scientists should research on the basic behaviors of nano material and methods to manipulate them. That will help us to develop an effective technology.
Applications of nanotech.
Applied nanotechnology spreads in a wide area. Some scientists say nanotechnology will replace each and every existing technology on earth. By now most of the branches of science have their own subcategories of nanotechnological approaches, like nano-medicine, nano-chemistry and nano-robotics. One way of categorizing these numerous applications are according to the fundamental nano materials which have been utilized in those applications. There are three main fundamental components; Nano-surfaces, Nano-particles and Nano-tubes.
Nano surfaces are surfaces with nano scale impressions which are developed by special treatment processes. Effective surface area (a) of nano-surface is extremely higher than a similar area of normal surface. Therefore unique features can be observed in nano-surfaces. For example, if we use a nano-surface as an electrode in a electrolyte fuel cell, since the electric current (I) generated by the cell is proportional to the surface area of the electrode (I α a), with the increased surface area of the nano-electrode, higher electric current can be generated. On nano-surfaces we will be able to build nano-chips with relatively high capacity and smaller solar panels which can harvest higher solar energy. Since nano surfaces have nano scale cavities they will trap almost all the particles and microbes thus nano surfaces can be used as highly effective filters. If the cavities are so small that nothing can enter them, then nothing will be able to make contacts with the surface. So those nano surfaces can be used to develop self cleaning roofs, walls, tiles, glass and even garments.
Nano-tubes are tubes which range within 1-100nm. They are usually developed by rolling around an atomic layer in the shape of a tube. Nano tube is a main part in nano-motors and nano-rotors. They can also be utilized as transporters when the ends of the tube are closed. Nano scale conducting lines can be constructed by attaching a series of nano-tubes at ends. Key component in nano wires and nano diodes are these nano tubes.
Some of nano particles and nano tubes belong to the universal group known as fullerenes. Fullerene is a general name given to hollowed structures developed by carbon atoms. Those structures either can be spherical or tubular. Spherical fullerenes are also known as Bucky-balls, which is a fascination in the field of nano science.
Even though humans invented it and developing it, in an one particular instance it will go out from human control to its own control, because principals of self assembly have been used from the very first initiation to create it. The results of self control is beyond our imaginations. Therefore even though it is not comfortable, we should know that future of this field is unpredictable. But as human intellects we can make some good speculations about the future of nanotechnology.
Nanotechnology beyond control can be a great danger. They can be categorized as primary impacts and secondary impacts.
Primary impacts are the damage directly done by the technology; nano-robots if not programmed well or if not under proper control can cause serious problems, enter living organisms and start destroying the cells by various mechanisms such as destroying proteins and mutating genetic material, change the electric sequences of the neurons and damage the brain thus resulting mental and physical disorders. Some of these can be lethal. Nano compounds can cause various incurable diseases.
Secondary impacts are the damage result through the primary impacts; impairments of mental and physical health will lead to social and behavioral problems, mutations in genetic material will result in new species which either can be good or bad.
Since the nano materials are super efficient, invisible to the naked eye and easily spreadable through any medium, without controlling methods, they can easily cause an invasion. Therefore if we are going to advance this technology, we should first research the fundamental properties and controlling methods of them. Then we should apply those methods to the technology in order to minimize the damage potential. We should also assess the technology all the time on their practical application.
But still we can’t assure a 100% harm free technology. Because nanotechnology at their higher stages will develop their own mutated properties which we still do not know. At that moment we will be defense less in front of our own technology. That is why it is so important to study all feasible behaviors of nano materials and systems. That will grant us a secure, practical and an effective novel technology.