Nanotechnology

Nanotechnology comprises technological developments on the nanometer scale, usually 0.1 to 100 nm (1/1,000 µm, or 1/1,000,000 mm). A possible way to interpret this size is to take the width of a hair, and imagine something ten thousand times smaller. The term has sometimes been applied to microscopic technology. Nanotechnology is any technology which exploits phenomena and structures that can only occur at the nanometer scale, which is the scale of several atoms and small molecules. The United States' National Nanotechnology Initiative website [1] defines it as follows: "Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications." Such phenomena include quantum confinement—which can result in different electromagnetic and optical properties of a material between nanoparticles and the bulk material; the Gibbs-Thomson effect—which is the lowering of the melting point of a material when it is nanometers in size; and such structures as carbon nanotubes.

Nanoscience and nanotechnology are an extension of the field of materials science, and materials science departments at universities around the world in conjunction with physics, mechanical engineering, bioengineering, and chemical engineering departments are leading the breakthroughs in nanotechnology. The related term nanotechnology is used to describe the interdisciplinary fields of science devoted to the study of nanoscale phenomena employed in nanotechnology. Nanoscience is the world of atoms, molecules, macromolecules, quantum dots, and macromolecular assemblies, and is dominated by surface effects such as Van der Waals force attraction, hydrogen bonding, electronic charge, ionic bonding, covalent bonding, hydrophobicity, hydrophilicity, and quantum mechanical tunneling, to the virtual exclusion of macro-scale effects such as turbulence and inertia. For example, the vastly increased ratio of surface area to volume opens new possibilities in surface-based science, such as catalysis.

History of use

The first mention of some of the distinguishing concepts in nanotechnology (but predating use of that name) was in "There's Plenty of Room at the Bottom," a talk given by physicist Richard Feynman at an American Physical Society meeting at Caltech on December 29, 1959. Feynman described a process by which the ability to manipulate individual atoms and molecules might be developed, using one set of precise tools to build and operate another proportionally smaller set, so on down to the needed scale. In the course of this, he noted, scaling issues would arise from the changing magnitude of various physical phenomena: gravity would become less important, surface tension and Van der Waals attraction would become more important, etc. This basic idea appears feasible, and exponential assembly enhances it with parallelism to produce a useful quantity of end products.

The term "nanotechnology" was defined by Tokyo Science University Professor Norio Taniguchi in a 1974 paper (N. Taniguchi, "On the Basic Concept of 'Nano-Technology'," Proc. Intl. Conf. Prod. Eng. Tokyo, Part II, Japan Society of Precision Engineering, 1974.) as follows: "'Nano-technology' mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or one molecule." In the 1980s the basic idea of this definition was explored in much more depth by Dr. Eric Drexler, who promoted the technological significance of nano-scale phenomena and devices through speeches and the books Engines of Creation: The Coming Era of Nanotechnology and Nanosystems: Molecular Machinery, Manufacturing, and Computation, (ISBN 0-471-57518-6), and so the term acquired its current sense.

More broadly, nanotechnology includes the many techniques used to create structures at a size scale below 100 nm, including those used for fabrication of nanowires, those used in semiconductor fabrication such as deep ultraviolet lithography, electron beam lithography, focused ion beam machining, nanoimprint lithography, atomic layer deposition, and molecular vapor deposition, and further including molecular self-assembly techniques such as those employing di-block copolymers. It should be noted, however, that all of these techniques preceded the nanotech era, and are extensions in the development of scientific advancements rather than techniques which were devised with the sole purpose of creating nanotechnology or which were results of nanotechnology research.

Technologies currently branded with the term 'nano' are little related to and fall far short of the most ambitious and transformative technological goals of the sort in molecular manufacturing proposals, but the term still connotes such ideas. Thus there may be a danger that a "nano bubble" will form from the use of the term by scientists and entrepreneurs to garner funding, regardless of (and perhaps despite a lack of) interest in the transformative possibilities of more ambitious and far-sighted work. The diversion of support based on the promises of proposals like molecular manufacturing to more mundane projects also risks creating a perhaps unjustifiedly cynical impression of the most ambitious goals: an investor intrigued by molecular manufacturing who invests in 'nano' only to find typical materials science advances result might conclude that the whole idea is hype, unable to appreciate the bait-and-switch made possible by the vagueness of the term. On the other hand, some have argued that the publicity and competence in related areas generated by supporting such 'soft nano' projects is valuable, even if indirect, progress towards nanotechnology's most ambitious goals.

Potential benefits

Nanotechnology covers a wide range of industries, and therefore the potential benefits are also widespread. Telecommunications and Information technology could benefit in terms of faster computers and advanced data storage.

Healthcare could see improvements in skin care and protection, advanced pharmaceuticals, drug delivery systems, biocompatible materials, nerve and tissue repair, and cancer treatments.

Other industries benefits include catalysts, sensors and magnetic materials and devices [2].

Potential risks

For the near-term, critics of nanotechnology point to the potential toxicity of new classes of nanosubstances that could adversely affect the stability of cell membranes or disturb the immune system when inhaled, digested or absorbed through the skin. Objective risk assessment can profit from the bulk of experience with long-known microscopic materials like carbon soot or asbestos fibres. Nanoparticles in the environment could potentially accumulate in the food chain. [3]

An often cited worst-case scenario is "grey goo", a hypothetical substance into which the surface objects of the earth might be transformed by self-replicating nanobots running amok.(Due to recent suggestions, this case has been proven as "impossible".)

Societal risks from the use of nanotechnology have also been raised, such as hypothetical nanotech weapons (e.g. a nanomachine which consumed the rubber in tires would quickly disable many vehicles), and in the creation of undetectable surveillance capabilities.

New materials, devices, technologies

Template:Cleanup-date

Manufacturing

When the term "nanotechnology" was independently coined and popularized by Eric Drexler, who at the time was unaware of Taniguchi's usage, it referred to a future manufacturing technology based on molecular machine systems. The premise was that molecular-scale biological analogies of traditional machine components demonstrated that molecular machines were possible, and that a manufacturing technology based on the mechanical functionality of these components (such as gears, bearings, motors, and structural members) would enable programmable, positional assembly to atomic specification (see the original reference PNAS-1981). The physics and engineering performance of exemplar designs were analyzed in the textbook Nanosystems.

Because the term "nanotechnology" was subsequently applied to other uses, new terms evolved to refer to this distinct usage: "molecular nanotechnology," "molecular manufacturing," and most recently, "productive nanosystems."

One alternative view is that designs such as those proposed by Drexler and Merkle do not accurately account for the electrostatic interactions and will not operate according to the results of the analysis in Nanosystems. The contention is that man-made nanodevices will probably bear a much stronger resemblance to other (less mechanical) nanodevices found in nature: cells, viruses, and prions. This idea is explored by Richard A. L. Jones in his book Soft Machines: Nanotechnology and Life (ISBN 0-19-852855-8).

Another view, put forth by Carlo Montemagno, is that future nanosystems will be hybrids of silicon technology and biological molecular machines, and his group's research is directed toward this end.

The seminal experiment proving that positional molecular assembly is possible was performed by Ho and Lee at Cornell University in 1999. They used a scanning tunneling microscope to move an individual carbon monoxide molecule (CO) to an individual iron atom (Fe) sitting on a flat silver crystal, and chemically bind the CO to the Fe by applying a voltage.

Though biology clearly demonstrates that molecular machine systems are possible, non-biological molecular machines are today only in their infancy. Leaders in research on non-biological molecular machines are Dr. Alex Zettl and his groups at Lawrence Berkeley Laboratories and UC Berkeley. They have constructed at least three distinct molecular devices whose motion is controlled from the desktop with changing voltage: a rotating molecular motor, a molecular actuator, and a nanoelectromechanical relaxation oscillator.

Manufacturing in the context of productive nanosystems is not related to, and should be clearly distinguished from, the conventional technologies used to manufacture nanomaterials such as carbon nanotubes and nanoparticles.

Key Characteristics

• Some nanodevices self-assemble. That is, they are built by mixing two or more complementary and mutually attractive pieces together so they make a more complex and useful whole. Other nanodevices must be built piece by piece in stages, much as manufactured items are currently made. Scanning probe microscopy is an important technique both for characterization and synthesis of nanomaterials. Atomic force microscopes and scanning tunneling microscopes can be used to look at surfaces and to move atoms around. By designing different tips for these microscopes, they can be used for carving out structures on surfaces and to help guide self-assembling structures. Atoms can be moved around on a surface with scanning probe microscopy techniques, but it is cumbersome, expensive and very time-consuming, and for these reasons it is quite simply not feasible to construct nanoscaled devices atom by atom. You don't want to assemble a billion transistors into a microchip by taking an hour to place each transistor, but these techniques may eventually be used to make primitive nanomachines, which in turn can be used to make more sophisticated nanomachines.

• 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 catalyst at nanoscales.

• "Nanosize" powder particles (a few nanometres 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 Daniel J. Shanefield, Kluwer Academic Publ., Boston.)

Problems

One of the problems facing nanotechnology concerns how to assemble atoms and molecules into smart materials and working devices. Supramolecular chemistry, a very important tool here, is the chemistry beyond the molecule, and molecules are being designed to self-assemble into larger structures. In this case, biology is a place to find inspiration: cells and their pieces are made from self-assembling biopolymers such as proteins and protein complexes. One of the things being explored is synthesis of organic molecules by adding them to the ends of complementary DNA strands such as ----A and ----B, with molecules A and B attached to the end; when these are put together, the complementary DNA strands hydrogen bonds into a double helix, ====AB, and the DNA molecule can be removed to isolate the product AB.

Advanced nanotechnology

Advanced nanotechnology, sometimes called molecular manufacturing, is a term given to the concept of engineered nanosystems (nanoscale machines) operating on the molecular scale. By the countless examples found in biology it is currently known that billions of years of evolutionary feedback can produce sophisticated, stochastically optimized biological machines, and it is hoped that developments in nanotechnology will make possible their construction by some shorter means, perhaps using biomimetic principles. However, K Eric Drexler and other researchers have proposed that advanced nanotechnology, although perhaps initially implemented by biomimetic means, ultimately could be based on mechanical engineering principles (see also mechanosynthesis)

In August 2005, a task force consisting of 50+ international experts from various fields was organized by the Center for Responsible Nanotechnology to study the societal implications of molecular nanotechnology [4].

Determining a set of pathways for the development of molecular nanotechnology is now an objective of a broadly based technology roadmap project [5] led by Battelle (the manager of several U.S. National Laboratories) and the Foresight Institute. That roadmap should be completed by early 2007.

Interdisciplinary ensemble

A definitive feature of nanotechnology is that it constitutes an interdisciplinary ensemble of several fields of the natural sciences that are, in and of themselves, actually highly specialized. Thus, physics plays an important role—alone in the construction of the microscope used to investigate such phenomena but above all in the laws of quantum mechanics.

See also

Wikibooks has more about this subject:

Nanowiki

• Femtotechnology
• List of nanotechnology topics
• Nanotechnology in fiction
• Mesotechnology
• Picotechnology
• Join the Wikireason: Nanotechnology debate

Prominent individuals in nanotechnology

• Richard Feynman - gave the first mention of some of the distinguishing concepts in a 1959 talk
• Norio Taniguchi - defined the term "nanotechnology"
• K. Eric Drexler - promoted the technological significance, described Grey goo scenario
• Robert Freitas - nanomedicine theorist
• Ralph Merkle - nanotechnology theorist
• Sumio Iijima - discoverer of nanotubes
• Richard Smalley - co-discoverer of buckminsterfullerene
• Harry Kroto - co-discoverer of buckminsterfullerene
• Erwin Müller - invented the field ion microscope, and the atom probe.
• Gerd Binnig - co-inventor of the scanning tunneling microscope
• Heinrich Rohrer - co-inventor of the scanning tunneling microscope
• Paul Alivisatos - Director of the Materials Sciences Division at the Lawrence Berkeley National Laboratory
• Chris Phoenix - co-founder of the Center for Responsible Nanotechnology
• Mike Treder - co-founder of the Center for Responsible Nanotechnology
• Phaedon Avouris - first electronic devices made out of carbon nanotubes
• Alex Zettl - Built the first molecular motor based on carbon nanotubes

External links

Databases

• Nanowerk - A free database to research over 1,300 nanomaterials from over 80 manufacturers

Journals and news

• Latest nanotechnology research news - Compiled by nanotechnologists
• Everything you wanted to know about nanotechnology — Provided by New Scientist.
• Nanotechnology and Nanomaterials A to Z
• Recent Developments In Nanotechnology
• Nanotechnology, electronic journal since 1990, available on web and CD-ROM.
• Nano Letters, electronic journal published by American Chemical Society.
• Journal of Nanoscience and Nanotechnology
• Journal of Computational and Theoretical Nanoscience
• Nanotechnology news and related research
• Nanotechnology news links - updated daily
• Nanotechnology basics, news, and general information
• Small Times: News about MEMS, Nanotechnology and Microsystems
• nanotechweb.org: nanotechnology news, products, jobs, events and information
• Nanowerk News — exclusive "Spotlight" articles and nanotech news updated daily
• Nanotechnology News & Headlines

Laboratories

• NanoLab Nijmegen
• Canada's Flagship Nanotechnology Institute
• University of Alberta's Nanofabrication Facility
• The London Centre for Nanotechnology / A research centre jointly set up by University College London and Imperial College London
• The California NanoSystems Institute
• Nanomagnetic Materials Research Group at UTA
• The Smalley Group / Carbon Nanotechnology Laboratory
• Center for Biological and Environmental Nanotechnology
• Bios: The Lab-on-a-Chip Group, Universiteit Twente
• Center for Nano & Molecular Science & Technology- CNM at UT Austin
• Center for Nanoscale Science and Technology at Rice University
• Advanced Micro/Nanodevices Lab at the University of Waterloo
• Cornell University Center for Nanoscale Systems
• Cornell NanoScale Science & Technology Facility (CNF)
• MESA+ Institute for Nanotechnology - Universiteit Twente
• The Kavli Institute of Nanoscience Delft
• NanoFab Research and Teaching Facility at the University of Texas at Arlington
• NanoTech Institute at the University of Texas at Dallas
• Nanotechnology Research Institute - National Institute of Advanced Industrial Science and Technology
• The MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
• Gracias Laboratory, Johns Hopkins University, Baltimore, MD
• Bellare Nanotech Laboratory, IIT Bombay, Mumbai, India

Nanotechnology and society

• Center for Responsible Nanotechnology
• Labor and Worklife Program at Harvard Law School, Nanotechnology Initiative
• ETC group Action group on Erosion, Technology and Concentration
• Bioethics and Disability Nanotechnology
• NanotechWatch.org Nanotechnology news: the hype and the reality of this emerging technology
• CNS-UCSB Center for Nanotechnology in Society
• Societal Dynamics of Nanoscale Science and Technology
• Nanozone Nanotechnology education for ages 8-14 and the public
• Nanotechnology Project - Friends of the Earth
• Friends of the Earth, "Nanotechnology Project — Criticism of nanotechnology.

References

ISBN links support NWE through referral fees

• Daniel J. Shanefield (1996). Organic Additives And Ceramic Processing. Kluwer Academic Publishers. ISBN 0792397657.. 

• Meridian Institute's Nanotechnology and Development News

• Project on Emerging Nanotechnologies

• Centre for Biological and Environmental Nanotechnology

• NanoBusiness Alliance

• Hunt, Geoffrey & Mehta, Michael (eds) (2006). Nanotechnology: Risk Ethics, & Law. Earthscan, London. 

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

• Nanotechnology  ^history

The history of this article since it was imported to New World Encyclopedia:

• History of "Nanotechnology"

Note: Some restrictions may apply to use of individual images which are separately licensed.