| • Science | • People | • Locations | • Timeline |
| Contents | ||
Due to the small size at which nanotechnology operates, physical phenomena not observed at the macroscopic scale dominate. These nanoscale phenomena include quantum size effects and short range forces such as van der Waals forces. Furthermore the vastly increased ratio of surface area to volume promotes surface phenomena. Since the progress of computers is growing exponentially it is believed that it will develop into nanotechnology in the near future.
In fiction and futurist writings, "nanotechnology" often refers to molecular nanotechnology (also known as "MNT"), a hypothetical advanced form of nanotechnology that is believed will be developed some time in the future.
The first mention of nanotechnology (not yet using that name) occurred in a talk given by Richard Feynman in 1959, entitled There's Plenty of Room at the Bottom. Feynman suggested a means to develop the ability to manipulate atoms and molecules "directly", by developing a set of one-tenth-scale machine tools analogous to those found in any machine shop. These small tools would then help to develop and operate a next generation of one-hundredth-scale machine tools, and so forth. As the sizes get smaller, we would have to redesign some tools because the relative strength of various forces would change. Gravity would become less important, surface tension would become more important, van der Waals attraction would become important, etc. Feynman mentioned these scaling issues during his talk. Nobody has yet effectively refuted the feasibility of his proposal.
The term 'Nano-Technology' was created by Tokyo Science University professor Norio Taniguchi in 1974 to describe the precision manufacture of materials with nanometer tolerances. In the 1980s the term was reinvented and its definition expanded by K Eric Drexler, particularly in his 1986 book . He explored this subject in much greater technical depth in his MIT doctoral dissertation, later expanded into Nanosystems: Molecular Machinery, Manufacturing, and Computation [1]. Computational methods play a key role in the field today because nanotechnologists can use them to design and simulate a wide range of molecular systems.
Natural or man-made particles or artifacts often have qualities and capabilities quite different from their macroscopic counterparts. Gold, for example, which is chemically inert at normal scales, can serve as a potent chemical catalystEnthalpy profile for catalysed and uncatalysed reactions. A is the activation energy for an uncatalysed reaction, A is the reduced activation energy for the same reaction when catalysed. I represents the point at which a chemical intermediate has been for at nanoscales.
"Nanosize" powder particles (a few nanometers in diameter, also called nano-particles) are potentially important in ceramics, powder metallurgy, the achievement of uniform nanoporosity, and similar applications. The strong tendency of small particles to form clumps ("agglomerates") is a serious technological problem that impedes such applications. However, a few dispersants such as ammonium citrate (aqueous) and imidazoline or oleyl alcohol (nonaqueous) are promising additives for deagglomeration. (Those materials are discussed in "Organic Additives And Ceramic Processing," by D. J. Shanefield, Kluwer Academic Publ., Boston.)
In October 2004, researchers at The University Of Manchester suceeded in forming a small piece of material only 1 atom thick called grapheneGraphene is a single planar sheet of sp˛ bonded carbon atoms. It is not an allotrope of carbon because the sheet is of finite size and other elements appear at the edge in nonvanishing stoichiometric ratios; a typical graphene would have the chemical form.