A basic definition: Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced.
In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products.
Nanotechnology Defined
Nanotechnology can perhaps be best defined as the ability to engineer new attributes through controlling features at a very small scale - at or around the scale of a nanometre. One nanometre is a billionth of a metre; or about 1/80,000 the width of a human hair. The use of materials at the ‘nano’ scale predates even the applications that are hitting the market now. Nanoparticles were used by the Romans to make glasses, and during the Renaissance period to make ceramics. However, although some elements were used in the past, it is the understanding of nanotechnology and how it can be used which is new. The nanoscale has become accessible both by application of new physical instruments and procedures and by further diminution of present microsystems.
When K. Eric Drexler (right below) popularized the word 'nanotechnology' in the 1980's, he was talking about building machines on the scale of molecules, a few nanometers wide—motors, robot arms, and even whole computers, far smaller than a cell. Drexler spent the next ten years describing and analyzing these incredible devices, and responding to accusations of science fiction. Meanwhile, mundane technology was developing the ability to build simple structures on a molecular scale. As nanotechnology became an accepted concept, the meaning of the word shifted to encompass the simpler kinds of nanometer-scale technology. The U.S. National Nanotechnology Initiative was created to fund this kind of nanotech: their definition includes anything smaller than 100 nanometers with novel properties.
Much of the work being done today that carries the name 'nanotechnology' is not nanotechnology in the original meaning of the word. Nanotechnology, in its traditional sense, means building things from the bottom up, with atomic precision. This theoretical capability was envisioned as early as 1959 by the renowned physicist Richard Feynman.
I want to build a billion tiny factories, models of each other, which are manufacturing simultaneously. . . The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big. — Richard Feynman, Nobel Prize winner in physics
Based on Feynman's vision of miniature factories using nanomachines to build complex products, advanced nanotechnology (sometimes referred to as molecular manufacturing) will make use of positionally-controlled mechanochemistry guided by molecular machine systems. Formulating a roadmap for development of this kind of nanotechnology is now an objective of a broadly based technology roadmap project led by Battelle (the manager of several U.S. National Laboratories) and the Foresight Nanotech Institute.
Shortly after this envisioned molecular machinery is created, it will result in a manufacturing revolution, probably causing severe disruption. It also has serious economic, social, environmental, and military implications.
Working at the nanometre level offers many opportunities for creating novel products; and any product, which possesses a characteristic, or attribute that involves some manipulation or measurement at or below 100 nanometres (or 0.1 of a micrometre) falls under the umbrella of nanotechnology. These include paints (with nanoparticles), medicines (coated drugs for targeted drug delivery), foodstuffs (‘taste-burst’ foods), clothing (stay-clean textiles with nano fibres), packaging (specially adapted polymers that prevent contamination and sense decay) and new materials for aerospace, automotive and construction applications (lightweight but tough, heat-resistant nanocomposites).
Governments worldwide are now spending close to £2.5billion on nanotechnology R&D, and this figure will continue to rise. The United States is leading the way, and full information is provided on their National Nanotechnology Initiative website (www.nano.gov). This website is run by the National Science Foundation (NSF), and, as befits an initiative that will spend over US$847 million on nanotechnology in 2004, is the most comprehensive governmental website on nanotechnology, full of reports, facts and figures. The agencies involved with the initiative include the Department of Defence, NASA and the Department of Energy.
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