From TheBestLinks.com
Nanotechnology develops minute technology; this is a model of "nanogears", only a few atoms wide.
Nanotechnology as a collective term refers to technological developments on the nanometre scale, usually 0.1-100nm. (One nanometre equals one thousandth of a micrometre or one millionth of a millimetre.) The term sometimes applies to any microscopic technology.
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 expotentially it is believed that it will develop into nanotechnology in the near future.
In fiction and media, "nanotechnology" often refers to hypothetical molecular nanotechnology (also known as "MNT").
Recent Breakthroughs
In September 2004, scientists encased silicon with gold and successfully detroyed tumor cells in mice.
Blood vessels inside tumors are quite different from normal blood vessels. When the scientists injected the silicon-gold material into the mice, it stuck inside of the blood vessels of the tumor. Then, they used infrared rays to heat up the afflicted area. Because gold is a metal, it heats up faster than flesh, and the result was heat. This heat was concentrated in the gold, and as such, it diffused outside into the tumor, destroying it. After this experiment, the mice remained tumor-free for 90 days.
History
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 Engines of Creation: The Coming Era of Nanotechnology. He explored this subject in much greater technical depth in his MIT doctoral dissertation, later expanded into Nanosystems: Molecular Machinery, Manufacturing, and Computation [1] (http://www.zyvex.com/nanotech/nanosystems.html). 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.
New materials, devices, technologies
Natural or man-made particles or artifacts often have qualities and capabilities quite different to their macroscopic counterparts. Gold, for example, which is chemically inert at normal scales, can serve as a potent chemical catalyst 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.)
Potential risks
An often cited, but not scientifically tangible worst-case scenario is the so-called grey goo, a substance into which the surface objects of the earth might be transformed by amok-running, self-replicating nano-robots. Defenders point out that smaller objects are more susceptible to damage from radiation and heat (due to greater surface area-to-volume ratios): nanomachines would quickly fail when exposed to harsh climates. More realistic are criticisms that point to the potential toxicity of new classes of nanosubstances that could adversely affect the stability of cell walls or disturb the immune system when inhaled or digested. Objective risk assessment can profit from the bulk of experience with long-known microscopic materials like carbon soot or asbestos fibres.
See also
Important People
Topics
External Links
References
Current useful reference works
Specialized additives for the difficult tasks of dispersing nanosize powders are discussed in "Organic Additives And Ceramic Processing," by D. J. Shanefield, Kluwer Academic Publishers, Boston, 1996.
Nanotechnology in fiction
Nanotechnology has also become a prominent theme in science fiction [2] (http://www.geocities.com/asnapier/nano/n-sf/), for example with the Borg in Star Trek, the Replicators in Stargate SG-1, the games Deus Ex and Metal Gear Solid, Alexandr Lazarevich' The NanoTech Network [3] (http://www.webcenter.ru/~lazarevicha/ntn_toc.htm), Greg Bear's Blood Music, Michael Crichton's Prey, and Neal Stephenson's book The Diamond Age.
da:Nanoteknologi
de:Nanotechnologie
es:Nanotecnología
fr:Nanotechnologie
ja:ナノテクノロジー
nl:Nanotechnologie
pl:Nanotechnologia
sv:Nanoteknologi
th:นาโนเทคโนโลยี
zh-cn:纳米科技
Related links
Top visited
0 of
0 links
[no links posted yet]
>> place link >>
Discussion
Last posted
0 of
0 messages
[no messages posted yet]
>> post message >>
Watch
You can
add this article to your own "watchlist" and receive e-mail notification about all changes in this page.
