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|موضوع: Nanotechnology الثلاثاء نوفمبر 09, 2010 2:47 pm|| |
What is Nanotechnology?
|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. || |
With 15,342 atoms, this parallel-shaft speed reducer gear is one of the largest nanomechanical devices ever modeled in atomic detail. LINK
Based on Feynman's vision of miniature factories using nanomachines to build complex products, advanced nanotechnology (sometimes referred to asmolecular manufacturing) will make use of positionally-controlledmechanochemistry guided by molecular machine systems. Formulating a roadmap for development of this kind of nanotechnology is now an objective of a broadly basedtechnology roadmap project led by Battelle (the manager of several U.S. National Laboratories) and the Foresight Nanotech Institute.
The Meaning of Nanotechnology
WhenK. Eric Drexler (right) 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 physicistRichard 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
Mihail (Mike) Roco of the U.S. National Nanotechnology Initiative has described four generations of nanotechnology development (see chart below). The current era, as Roco depicts it, is that of passive nanostructures, materials designed to perform one task. The second phase, which we are just entering, introduces active nanostructures for multitasking; for example, actuators, drug delivery devices, and sensors. The third generation is expected to begin emerging around 2010 and will feature nanosystems with thousands of interacting components. A few years after that, the first integrated nanosystems, functioning (according to Roco) much like a mammalian cell with hierarchical systems within systems, are expected to be developed.Some experts may still insist that nanotechnology can refer to measurement or visualization at the scale of 1-100 nanometers, but a consensus seems to be forming aroundthe idea (put forward by the NNI's Mike Roco) that control and restructuring of matter at the nanoscale is a necessary element. CRN's definition is a bit more precise than that, but as work progresses through the four generations of nanotechnology leading up to molecular nanosystems, which will include molecular manufacturing, we think it will become increasingly obvious that "engineering of functional systems at the molecular scale" is what nanotech is really all about.
Shortly after this envisioned molecular machinery is created, it will result in amanufacturing revolution, probably causing severe disruption. It also has serious economic, social, environmental, and military implications. Four Generations
General-Purpose TechnologyNanotechnology is sometimes referred to as a general-purpose technology. That's because in its advanced form it will have significant impact on almost all industries and all areas of society. It will offer better built, longer lasting, cleaner, safer, and smarter products for the home, for communications, for medicine, for transportation, for agriculture, and for industry in general.
Conflicting Definitions Unfortunately, conflicting definitions of nanotechnology and blurry distinctions between significantly different fields have complicated the effort to understand the differences and develop sensible, effective policy. The risks of today's nanoscale technologies (nanoparticle toxicity, etc.) cannot be treated the same as the risks of longer-term molecular manufacturing (economic disruption, unstable arms race, etc.). It is a mistake to put them together in one basket for policy consideration—each is important to address, but they offer different problems and will require different solutions. As used today, the term nanotechnology usually refers to a broad collection of mostly disconnected fields. Essentially, anything sufficiently small and interesting can be called nanotechnology. Much of it is harmless. For the rest, much of the harm is of familiar and limited quality. But as we will see, molecular manufacturing will bring unfamiliar risks and new classes of problems.
Dual-Use TechnologyLike electricity or computers before it, nanotech will offer greatly improved efficiency in almost every facet of life. But as a general-purpose technology, it will be dual-use, meaning it will have many commercial uses and it also will have many military uses—making far more powerful weapons and tools of surveillance. Thus it represents not only wonderfulbenefits for humanity, but also grave risks.
Imagine a medical device that travels through the human body to seek out and destroy small clusters of cancerous cells before they can spread. Or a box no larger than a sugar cube that contains the entire contents of the Library of Congress. Or materials much lighter than steel that possess ten times as much strength. — U.S. National Science Foundation
A key understanding of nanotechnology is that it offers not just better products, but a vastly improved manufacturing process. A computer can make copies of data files—essentially as many copies as you want at little or no cost. It may be only a matter of time until the building of products becomes as cheap as the copying of files. That's the real meaning of nanotechnology, and why it is sometimes seen as "the next industrial revolution."
The power of nanotechnology can be encapsulated in an apparently simple device called a personal nanofactory that may sit on your countertop or desktop. Packed with miniature chemical processors, computing, and robotics, it will produce a wide-range of items quickly, cleanly, and inexpensively, building products directly from blueprints.◄ Click to enlarge
My own judgment is that the nanotechnology revolution has the potential to change America on a scale equal to, if not greater than, the computer revolution. — U.S. Senator Ron Wyden (D-Ore.)
Artist's Conception of a Personal Nanofactory
Courtesy of John Burch,Lizard Fire Studios (3D Animation, Game Development)Exponential ProliferationNanotechnology not only will allow making many high-quality products at very low cost, but it will allow making new nanofactories at the same low cost and at the same rapid speed.This unique (outside of biology, that is) ability to reproduce its own means of production is why nanotech is said to be an exponential technology. It represents a manufacturing system that will be able to make more manufacturing systems—factories that can build factories—rapidly, cheaply, and cleanly. The means of production will be able to reproduce exponentially, so in just a few weeks a few nanofactories conceivably could become billions. It is a revolutionary, transformative, powerful, and potentially verydangerous—orbeneficial—technology.
How soon will all this come about? Conservative estimates usually say 20 to 30 years from now, or even much later than that. However, CRN is concerned that it may occursooner, quite possibly within the next decade. This is because of the rapid progress being made in enabling technologies, such as optics, nanolithography, mechanochemistry and 3D prototyping. If it does arrive that soon, we may not be adequatelyprepared, and the consequences could be severe.
We believe it's not too early to begin asking some toughquestions and facing the issues:
|Who will own the technology? |
|Will it be heavily restricted, or widely available? |
|What will it do to the gap between rich and poor? |
|How can dangerous weapons be controlled, and perilous arms races be prevented? |
Many of these questions were first raised over a decade ago, and have not yet been answered. If the questions are not answered with deliberation, answers will evolve independently and will take us by surprise; the surprise is likely to be unpleasant.
It is difficult to say for sure how soon this technology will mature, partly because it's possible (especially in countries that do not have open societies) that clandestine military or industrial development programs have been going on for years without our knowledge.
We cannot say with certainty that full-scale nanotechnology will not be developed with the next ten years, or even five years. It may take longer than that, but prudence—and possibly our survival—demands that weprepare now for the earliest plausible development scenario.
More Background on Nanotechnology:
|Nanotechnology Basics - For students and other learners |
|Managing Magic - A brief overview of the challenges posed by advanced nanotechnology|
|Nanotechnology on an Upward Slope - An online PowerPoint presentation|
| Turn on the Nanotech High Beams - An essay published by Future Brief|
|Nano Simulation -A way to visualize what is meant by molecular manufacturing|
| Debating the Future of Nanotechnology - Perspective from the Foresight Institute|
|Safe Utilization of Advanced Nanotechnology - One of the founding papers of CRN|
|5-Minute Nanosystems - A quick summary of Eric Drexler's foundational work on nanotechnology|
|Nanotechnology Press Kit - Compiled and published by Nanotechnology Now |
عدد الرسائل : 1536
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|موضوع: رد: Nanotechnology الثلاثاء نوفمبر 09, 2010 3:34 pm|| |
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