Difference between revisions of "Nanotechnology" - New World Encyclopedia

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[[Image:Nanogearandbug.jpg|thumb|250px|right|A [[mite]] next to a [[gear]] set produced using [[MEMS]], the precursor to nanotechnology. Courtesy Sandia National Laboratories, SUMMiTTM Technologies, www.mems.sandia.gov]]
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'''Nanotechnology''' comprises [[technology|technological]] developments on the [[nanometer]] scale, usually 0.1 to 100 nm (1/1,000 [[micrometre|µm]], or  
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'''Nanotechnology''' comprises [[technology|technological]] developments on the [[nanometer]] scale, usually 0.1 to 100 nm. (One nanometer equals one thousandth of a [[micrometre]] or one millionth of a [[millimetre]].) The term has sometimes been applied to [[microscope|microscopic]] technology. This article discusses nanotechnology, nanoscience, and [[molecular nanotechnology]].  
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1/1,000,000 [[millimetre|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 [[microscope|microscopic]] technology.  
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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 [http://www.nano.gov/html/facts/whatIsNano.html] 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]].  
  
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==Intro==
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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, [[macromolecule]]s, [[quantum dot]]s, and macromolecular assemblies, and is dominated by surface effects such as [[Van der Waals force]] attraction, [[hydrogen bond]]ing, electronic charge, [[ionic bond]]ing, [[covalent bond]]ing, [[hydrophobe|hydrophobicity]], [[hydrophile|hydrophilicity]], and [[quantum tunneling|quantum mechanical tunneling]], to the virtual exclusion of [[macroscopic|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]].
  
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===Definition===
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==History of use==
  
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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]] [http://www.nano.gov/html/facts/whatIsNano.html website] 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 including [[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.
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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.
  
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The related term '''nanoscience''' is used to describe the [[interdisciplinary]] fields of science devoted to the study of nanoscale phenomena employed in nanotechnology. This is the world of atoms, molecules, [[macromolecule]]s, [[quantum dot]]s, and macromolecular assemblies, and is dominated by surface effects such as [[Van der Waals force]] attraction, [[hydrogen bond]]ing, electronic charge, [[ionic bond]]ing, [[covalent bond]]ing, [[hydrophobe|hydrophobicity]], [[hydrophile|hydrophilicity]], and [[quantum tunneling|quantum mechanical tunneling]], to the virtual exclusion of [[macroscopic|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]].
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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 [[Eric Drexler| 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.
  
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===History of Use===
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More broadly, nanotechnology includes the many techniques used to create structures at a size scale below 100 nm, including those used for fabrication of [[nanowire]]s, those used in [[semiconductor fabrication]] such as deep ultraviolet [[photolithography|lithography]], [[electron beam lithography]], focused [[ion beam]] machining, [[nanoimprint lithography]], [[chemical vapor deposition|atomic layer deposition, and molecular vapor deposition]], and further including [[self-assembly|molecular self-assembly]] techniques such as those employing di-block [[copolymer]]s. 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.
  
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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.
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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_(economics)|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 [[Technology_hype|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.
  
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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 [[Eric Drexler| 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.
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==Potential benefits==
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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.  
  
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More broadly, nanotechnology includes the many techniques used to create structures at a size scale below 100 nm, including those used for fabrication of [[nanowire]]s, those used in [[semiconductor fabrication]] such as deep ultraviolet [[photolithography|lithography]], [[electron beam lithography]], focused [[ion beam]] machining,[[Nanoimprint Lithography]] [[chemical vapor deposition|atomic layer deposition, and molecular vapor deposition]], and further including [[self-assembly|molecular self-assembly]] techniques such as those employing di-block [[copolymer]]s. It should be noted, however, that all of these techniques preceeded 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.
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Healthcare could see improvements in skin care and protection, advanced [[pharmaceuticals]], drug delivery systems, [[biocompatible]] materials, [[nerve]] and [[tissue engineering|tissue repair]], and [[Cancer#Nanotechnology_treatments|cancer]] treatments.  
  
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The term nanotechnology is sometimes conflated with the more specific [[molecular nanotechnology]] (also known as "MNT"), a proposed form of advanced nanotechnology based on [http://www.e-drexler.com/ productive nanosystems]. Molecular nanotechnology would fabricate precise structures using [[mechanosynthesis]] to perform [http://wise-nano.org/ molecular manufacturing]. Molecular nanotechnology, though not yet extant, is expected to have a [http://www.crnano.org/overview.htm great impact] on society if realized. In August 2005, a [http://www.crnano.org/CTF.htm 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.
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Other industries benefits include [[catalyst]]s, sensors and magnetic materials and devices [http://www.dti.gov.uk/innovation/nanotechnologyreport.pdf]. <!--Suggest this should be a summary section, not contain detailed explanations of one particular technology —>
  
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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_(economics)|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 [[Technology_hype|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.
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==Potential risks==
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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 membrane]]s 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]]. [http://dx.doi.org/10.1093/toxsci/kfi339]
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An often cited worst-case [[scenario planning|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".)
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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==
 
==New materials, devices, technologies==
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<<CLEAN UP THIS SECTION>>
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{{cleanup-date|November 2005}}
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===Manufacturing===
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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 [http://www.imm.org/PNAS.html PNAS-1981]).  The physics and engineering performance of exemplar designs were analyzed in the textbook [http://e-drexler.com/p/idx04/00/0411nanosystems.html Nanosystems].
  
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As manufacturing technology becomes more sophisticated it naturally enters the realm of what is arbitrarily labeled nanotechnology. Nanotechnology is based on the fact that the [[properties]] of materials become markedly different when their size approaches that of a few hundreds or tens of atoms. [[Nanoparticle]]s (nanometer sized clusters of atoms), for example, have proved useful in [[catalysis]]. A material that is catalytically inactive on the [[Macroscopic|macroscale]] can behave as a very efficient catalyst when in the form of nanoparticles. For this and other reasons, if [[nanorobot|nanobots]] are ever created they will not simply be scaled down versions of contemporary robots (an image popularised by [[Eric Drexler]]). The different physics at these scales means that man-made nanodevices will probably bear much stronger resemblance to nature's nanodevices: made from [[protein]]s, [[DNA]] and [[biological membrane|membranes]], much like viruses. This idea is explored by [[Richard A. L. Jones]] in his book ''Soft Machines: Nanotechnology and Life'' (ISBN 0-19-852855-8).
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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."
  
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One fundamental characteristic of nanotechnology is that nanodevices self-assemble. That is, they build themselves from the bottom up. [[Scanning probe microscopy]] is an important technique both for characterization and synthesis of nanomaterials. [[Atomic force microscope]]s and [[scanning tunneling microscope]]s 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 can be used for things like helping to guide self-assembling systems.
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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 [http://e-drexler.com/p/idx04/00/0411nanosystems.html 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).
  
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One of the problems facing nanotechnology is how to assemble atoms and molecules into smart materials and working devices. [[Supramolecular chemistry]] is here a very important tool. Supramolecular chemistry is the chemistry beyond the molecule, and molecules are being designed to [[self-assembly|self-assemble]] into larger structures. In this case, biology is a place to find inspiration: cells and their pieces are made from self-assembling [[biopolymer]]s such as [[protein]]s and protein complexes. One of the things being explored is synthesis of [[organic compound|organic molecules]] by adding them to the ends of [[complementary DNA]] [[DNA#Overview of molecular structure|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.
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Another view, put forth by [http://www.cnsi.ucla.edu/institution/personnel?personnel%5fid=105488 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.
  
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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.
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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.
  
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"Nanosize" powder particles (a few nanometres in diameter, also called nano-particles) are potentially important in [[ceramic]]s, [[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.)
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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 [http://www.lbl.gov/Science-Articles/Research-Review/Magazine/2001/Fall/features/02Nanotubes.html rotating molecular motor], a [http://www.physics.berkeley.edu/research/zettl/pdf/312.NanoLett5regan.pdf molecular actuator], and a [http://www.lbl.gov/Science-Articles/Archive/sabl/2005/May/Tiniest-Motor.pdf nanoelectromechanical relaxation oscillator].
  
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In October 2004, researchers at the [[University of Manchester]] succeeded in forming a small piece of material only 1 atom thick called [[graphene]].[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15499015] [[Robert Freitas]] has suggested that graphene might be used as a [[deposition (chemistry)|deposition]] surface for a [[diamondoid]] [[mechanosynthesis]] tool.[http://www.molecularassembler.com/Papers/PathDiamMolMfg.htm]
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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.
  
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As of [[August 23]] 2004, [[Stanford University]] has been able to construct a transistor from single-walled carbon nanotubes and organic molecules. These single-walled carbon nanotubes are basically a rolled up sheet of carbon atoms. They have accomplished creating this transistor making it two nanometers wide and able to maintain current three nanometers in length. To create this transistor they cut metallic nanotubes in order to form electrodes, and afterwards placed one or two organic materials to form a [[semiconductor|semiconducting]] channel between the [[electrode]]s. It is projected that this new achievement will be available in different applications in two to five years.
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===Key Characteristics===
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*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 microscope]]s and [[scanning tunneling microscope]]s 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.
  
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[http://news.com.com/Barrett+No+end+in+sight+for+Moores+Law/2100-1006_3-5594779.html News.com] reported on [[March 1st]] [[2005]] that [[Intel]] is preparing to introduce [[central processing unit|processors]] with features measuring 65 nanometers. The company’s current engineers believe that 5 nanometer processes are actually proving themselves to be more and more feasible. The company showed pictures of these transistor prototypes measuring 65, 45, 32, and 22 nanometers. However, the company spoke about how their expectations for the future are for new processors featuring 15,10, 7, and 5 nanometers.
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*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.
  
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Currently the prototypes use [[CMOS]] (complementary metal-oxide semiconductors); however, according to Intel smaller scales will rely on quantum dots, polymer layers, and nanotube technology.
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*"Nanosize" powder particles (a few nanometres in diameter, also called nano-particles) are potentially important in [[ceramic]]s, [[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.)
  
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[http://www.PhysOrg.com PhysOrg.com] writes about the use of [[plasmons]] in the world. Plasmons are waves of electrons traveling along the surface of metals. They have the same frequency and [[electromagnetic field]] as light; however, the sub-wavelength size allows them to use less space. These plasmons act like light waves in glass on metal, allowing engineers to use any of the same tricks such as multiplexing, or sending multiple waves. With the use of plasmons information can be transferred through chips at an incredible speed; however, these plasmons do have drawbacks. For instance, the distance plasmons travel before dying out depends on the metal, and even currently they can travel several millimeters, while chips are typically about a centimeter across from each other. In addition, the best metal currently available for plasmons to travel farther is aluminum. However, most industries that manufacture chips use copper over aluminum since it is a better [[electrical conduction|electrical conductor]]. Furthermore, the [[computer cooling|issue of heat]] will have to be looked upon. The use of plasmons will definitely generate heat but the amount is currently unknown.
 
  
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The further developments in the field of nanotechnology focuses on the [[oscillation]] of a nanomachine for [[telecommunication]]. The article states that in Boston an antenna-like sliver of [[silicon]] one-tenth the width of a human hair oscillated in a lab in a [[Boston University]] basement. This team led by Professor Pritiraj Mohanty developed the sliver of silicon. Since the technology functions at the speeds of [[gigahertz]] this could help make communication devices smaller and exchange information at gigahertz speeds. This nanomachine is comprised of 50 billion atoms and is able to oscillate at 1.49 billion times per second. The antenna moves over a distance of one-tenth of a [[picometer]].
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===Problems===
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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-assembly|self-assemble]] into larger structures. In this case, biology is a place to find inspiration: cells and their pieces are made from self-assembling [[biopolymer]]s such as [[protein]]s and protein complexes. One of the things being explored is synthesis of [[organic compound|organic molecules]] by adding them to the ends of [[complementary DNA]] [[DNA#Overview of molecular structure|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==
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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, [[stochastic]]ally 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 [http://www.crnano.org/developing.htm other researchers] have proposed that advanced nanotechnology, although perhaps initially implemented by biomimetic means, ultimately could be based on mechanical engineering principles.
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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, [[stochastic]]ally 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 [http://www.crnano.org/developing.htm 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]])
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Sandia National Labs currently produces "Self Assembling Nano Inks" which can be used in standard inkjet printers.
 
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As the inks dry they assemble into arrays, cavities, q-dots etc.
 
  
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A company called nanoink builds a "rapid prototyping" nano structure fabication machine which picks up atom chains and deposits them in a precise manner per the build file.
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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 [http://www.crnano.org/CTF.htm].
  
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Determining a set of pathways for the development of [[molecular nanotechnology]] is now an objective of a broadly based [[technology roadmaps|technology roadmap]] project [http://physorg.com/news4656.html] led by [[Battelle Memorial Institute | Battelle]] (the manager of several U.S. National Laboratories) and the [[Foresight Institute]]. That roadmap should be completed by late 2006. In August 2005, a [http://www.crnano.org/CTF.htm task force] consisting of 50+ international experts from various fields was organized by the [[Center for Responsible Nanotechnology]] to study the societal implications of advanced nanotechnology.
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Determining a set of pathways for the development of [[molecular nanotechnology]] is now an objective of a broadly based [[technology roadmaps|technology roadmap]] project [http://physorg.com/news4656.html] led by [[Battelle Memorial Institute | Battelle]] (the manager of several U.S. National Laboratories) and the [[Foresight Institute]]. That roadmap should be completed by early [[2007]].
  
 
==Interdisciplinary ensemble==
 
==Interdisciplinary ensemble==
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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]]
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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]].
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==Potential risks==
 
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===Goo===
 
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An often cited worst-case for everyone [[scenario planning|scenario]] is "[[grey goo]]", a hypothetical substance into which the surface objects of the earth might be transformed by self-replicating [[nanobots]] running amok, a process which has been termed [[global ecophagy]]. Defenders point out that smaller objects are more susceptible to damage from [[background radiation|radiation]] and heat (due to greater surface area-to-volume ratios): nanomachines would quickly fail when exposed to harsh climates. This argument depends on the speed of which such nanomachines might be able to reproduce.  
 
  
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Recently, [http://www.crnano.org/PR-IOP.htm new analysis] has shown that this "grey goo" danger is less likely than originally thought.  [[K. Eric Drexler]] considers an accidental "[[grey goo]]" scenario extremely unlikely and says so in later editions of ''Engines of Creation''.  The "[[grey goo]]" scenario begs the Tree Sap Answer: what chances exist that one's car could spontaneously mutate into a wild car, run off-road and live in the forest off tree sap? However, other long-term major risks to society and the environment have been identified.
 
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A variant on this is "[[Green Goo]]", a scenario in which [[nanobiotechnology]] creates a self-replicating nano machine which consumes all organic particles, living or dead, creating a slime -like non-living organic mass.
 
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Both of these would, however, be limited by the same mechanism limiting all life forms (who generally already behave this way): available energy.
 
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===Poison/Toxicity===
 
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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 or digested. Objective risk assessment can profit from the bulk of experience with long-known microscopic materials like carbon soot or asbestos fibres.
 
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There is a possibility that nanoparticles in drinking water could be dangerous to humans and/or other animals. Colon cells exposed to nano titanium dioxide particles have been found to decay at a quicker than normal rate. Titanium dioxide nanoparticles are often used in sunscreens, as they make them transparent, compared to bigger titanium dioxide particles, which make the sunscreen appear white.
 
−
 
−
===Weapons===
 
−
The weaponization of nanotechnology is a potential application. While advanced nanomaterials obviously have applications for improving existing weapons and military hardware through novel properties (such as improved strength to weight ratios or modified reflectivity to EM radiation for stealth applications), and molecular electronics could be used to build ruggedized computer systems for missiles, there is no obvious way for nanotechnology in any of its practical forms nowadays and into the foreseeable future to be weaponized beyond what is already possible with other technologies such as genetic engineering. While conceivably we could design nanomachines which attacked biological systems or the components of vehicles (i.e. a nanomachine which consumed the rubber in tires would quickly disable many vehicles), such designs are a far off concept.  In terms of efficacy, they might be compared to weapon concepts such as genetically engineered bacteria or viruses, which are similar in intended and practical function and still generally are unattractive tactical weapons, though their terrorism applications are clear.
 
−
 
−
Nanotechnology could be used to create highly undetectable or concealable surveillance devices - molecular sized microphones, cameras, and homing beacons are well within the realms of possibility.  The societal impact of such devices would depend on many factors, including who has access to them, how well they work, and how they are used.
 
  
  
 
== See also ==
 
== See also ==
 +
{{wikibookspar||Nanowiki}}
 +
* [[Femtotechnology]]
 
* [[List of nanotechnology topics]]
 
* [[List of nanotechnology topics]]
 +
* [[Nanotechnology in fiction]]
 +
* [[Mesotechnology]]
 +
* [[Picotechnology]]
 +
* Join the [[Wikireason: Nanotechnology]] debate
  
 
=== Prominent individuals in nanotechnology ===
 
=== Prominent individuals in nanotechnology ===
−
* [[Richard Feynman]]
+
* [[Richard Feynman]] -  gave the first mention of some of the distinguishing concepts in a 1959 talk
−
* [[Norio Taniguchi]]
+
* [[Norio Taniguchi]] - defined the term "nanotechnology"
−
* [[K. Eric Drexler]]
+
* [[K. Eric Drexler]] - promoted the technological significance, described [[Grey goo]] scenario
−
* [[Robert Freitas]]
+
* [[Robert Freitas]] - nanomedicine theorist
−
* [[Ralph Merkle]]
+
* [[Ralph Merkle]] -  nanotechnology theorist
−
* [[Sumio Iijima]]
+
* [[Sumio Iijima]] - discoverer of [[nanotubes]]
−
* [[Richard Smalley]]
+
* [[Richard Smalley]] - co-discoverer of [[buckminsterfullerene]]
−
* [[Erwin Müller]]
+
* [[Harry Kroto]] - co-discoverer of [[buckminsterfullerene]]
−
* [[Gerd Binnig]]
+
* [[Erwin Müller]] - invented the [[field ion microscope]], and the [[atom probe]].
−
* [[David Britz]]
+
* [[Gerd Binnig]] - co-inventor of the [[scanning tunneling microscope]]
−
* [[Heinrich Rohrer]]
+
* [[Heinrich Rohrer]] - co-inventor of the [[scanning tunneling microscope]]
−
* [[Raymond Kurzweil]]
+
* [[Paul Alivisatos]] - Director of the Materials Sciences Division at the Lawrence Berkeley National Laboratory
−
* [[Paul Alivisatos]]
+
* [[Chris Phoenix]] - co-founder of the [[Center for Responsible Nanotechnology]]
−
* [[Chris Phoenix]]
+
* [[Mike Treder]] - co-founder of the [[Center for Responsible Nanotechnology]]
−
* [[Mike Treder]]
+
* [[Phaedon Avouris]] - first electronic devices made out of [[carbon nanotubes]]
−
* [[Tim McKnight]]
+
* Alex Zettl - Built the first molecular motor based on carbon nanotubes
−
* [[Phaedon Avouris]]
 
−
* [[James Fraser Stoddart]]
 
−
* [[Richard Colton]]
 
  
 
== External links ==
 
== External links ==
  
−
====Articles====
+
====Databases====
−
* [http://www.smalltimes.com/document_display.cfm?document_id=7161 Molecular Nanotechnology: Fully Loaded with Benefits and Risks], by Mike Treder, published 2004 in [http://www.wfs.org/futurist.htm ''The Futurist'']
+
* [http://www.nanowerk.com/ Nanowerk] - A free database to research over 1,300 nanomaterials from over 80 manufacturers
−
* [http://www.nanoindian.com Nanotechnology in India] Nanotechnology Gateway of India
 
−
* [http://topics.developmentgateway.org/nanotechnology Nanotechnology for Development]
 
−
* [http://www.trnmag.com/Stories/2005/030905/Nanotubes_boost_molecular_devices_Brief_030905.html Stanford University transistors]
 
−
* [http://mprc.pku.edu.cn/courses/architecture/spring2005/20nmpressfoils.pdf Intel prototypes]
 
−
* [http://news.com.com/Barrett+No+end+in+sight+for+Moores+Law/2100-1006_3-5594779.html News.com, March 1 2005 "Barrett: No end in sight for Moore's Law"]
 
−
* [http://pubs.acs.org/cen/coverstory/8148/8148counterpoint.html Drexler and Smalley make the case for and against 'molecular assemblers']
 
−
* Margaret E. Kosal, [http://www.thebulletin.org/article.php?art_ofn=so04kosal "Is Small Scary?"], ''Bulletin of the Atomic Scientists'', September/October 2004.
 
−
* [http://www.isracast.com/tech_news/091205_tech.htm Nano armor - Protecting the soldiers of tomorrow] - An article from IsraCast
 
−
* [http://store.britannica.com/content/pdf/Nanotech.pdf "Nanotechnology"]. First two pages of article from the ''Encyclopaedia Britannica'' via the Encyclopaedia Britannica Store.
 
  
−
====Journals and News====
+
====Journals and news====
−
* [http://www.nanowerk.com Nanowerk News] — news updated daily
+
* [http://www.nanodaddy.com Latest nanotechnology research news] - Compiled by nanotechnologists
−
* [http://www.nanodaddy.com Hot Research Articles in Nanotechnology]- Compiled by Nanotechnologists
+
* [http://www.newscientist.com/channel/mech-tech/nanotechnology Everything you wanted to know about nanotechnology] — Provided by ''[[New Scientist| New Scientist]]''.
−
* [http://nanonovus.com — daily weblog
 
−
*[http://CRNano.typepad.com Responsible Nanotechnology] - daily weblog
 
−
* [http://www.nanotechnology.com/blogs/blognano Darrell Brookstein of nanotechnology.com] - daily weblog
 
−
* [http://www.nanotechnology.com/blogs/steveedwards Steve Edwards of nanotechnology.com] - daily weblog
 
−
* [http://www.nanobound.com Nanobound Weblog] - daily weblog
 
 
* [http://www.azonano.com/Materials.asp?Letter=_ Nanotechnology and Nanomaterials A to Z]
 
* [http://www.azonano.com/Materials.asp?Letter=_ Nanotechnology and Nanomaterials A to Z]
 
* [http://www.whatsnextnetwork.com/technology/index.php?cat=65 Recent Developments In Nanotechnology]
 
* [http://www.whatsnextnetwork.com/technology/index.php?cat=65 Recent Developments In Nanotechnology]
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* [http://www.smalltimes.com/ Small Times: News about MEMS, Nanotechnology and Microsystems]
 
* [http://www.smalltimes.com/ Small Times: News about MEMS, Nanotechnology and Microsystems]
 
* [http://nanotechweb.org nanotechweb.org: nanotechnology news, products, jobs, events and information]
 
* [http://nanotechweb.org nanotechweb.org: nanotechnology news, products, jobs, events and information]
 +
* [http://www.nanowerk.com Nanowerk News] — exclusive "Spotlight" articles and nanotech news updated daily
 +
* [http://home.businesswire.com/portal/site/home/index.jsp?epi-content=REDIRECT&epi-process=process_redirect.jsp&mtitle=VNS_TOPIC&vnsId=3304 Nanotechnology News & Headlines]
  
 
====Laboratories====
 
====Laboratories====
 +
* [http://www.ru.nl/nanolab/ Nano''Lab'' Nijmegen]
 
* [http://www.nint.ca/ Canada's Flagship Nanotechnology Institute]
 
* [http://www.nint.ca/ Canada's Flagship Nanotechnology Institute]
 
* [http://www.nanofab.ualberta.ca/ University of Alberta's Nanofabrication Facility]
 
* [http://www.nanofab.ualberta.ca/ University of Alberta's Nanofabrication Facility]
−
* [http://www.memsnet.org/ The MEMS and Nanotechnology Clearinghouse / The world's most popular portal for Nanotechnology information, jobs, and events]
 
 
* [http://www.london-nano.ucl.ac.uk/ The London Centre for Nanotechnology / A research centre jointly set up by University College London and Imperial College London]
 
* [http://www.london-nano.ucl.ac.uk/ The London Centre for Nanotechnology / A research centre jointly set up by University College London and Imperial College London]
 
* [http://www.cnsi.ucla.edu/ The California NanoSystems Institute]
 
* [http://www.cnsi.ucla.edu/ The California NanoSystems Institute]
−
* [http://www.mems-exchange.org/ The MEMS and Nanotechnology Exchange / A repository of Nanotechnology fabrication information]
+
* [http://www.uta.edu/physics/research/jpliu/myweb/ Nanomagnetic Materials Research Group at UTA]
 
* [http://smalley.rice.edu/ The Smalley Group / Carbon Nanotechnology Laboratory]
 
* [http://smalley.rice.edu/ The Smalley Group / Carbon Nanotechnology Laboratory]
 
* [http://cben.rice.edu/ Center for Biological and Environmental Nanotechnology]
 
* [http://cben.rice.edu/ Center for Biological and Environmental Nanotechnology]
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* [http://unit.aist.go.jp/nanotech/index.html Nanotechnology Research Institute] - [[National Institute of Advanced Industrial Science and Technology]]
 
* [http://unit.aist.go.jp/nanotech/index.html Nanotechnology Research Institute] - [[National Institute of Advanced Industrial Science and Technology]]
 
* [http://www.macdiarmid.ac.nz/ The MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand]
 
* [http://www.macdiarmid.ac.nz/ The MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand]
 +
* [http://www.jhu.edu/chbe/gracias/ Gracias Laboratory, Johns Hopkins University, Baltimore, MD]
 +
* [http://www.che.iitb.ac.in/faculty/jb/ Bellare Nanotech Laboratory, IIT Bombay, Mumbai, India]
  
−
====Nanotechnology and Society====
+
====Nanotechnology and society====
−
*[http://CRNano.org Center for Responsible Nanotechnology]
+
* [http://CRNano.org Center for Responsible Nanotechnology]
−
*[http://www.law.harvard.edu/programs/lwp Labor and Worklife Program at Harvard Law School, Nanotechnology Initiative]
+
* [http://www.law.harvard.edu/programs/lwp Labor and Worklife Program at Harvard Law School, Nanotechnology Initiative]
−
*[http://www.etcgroup.org ETC group] Action group on Erosion, Technology and Concentration
+
* [http://www.etcgroup.org ETC group] Action group on Erosion, Technology and Concentration
−
*[http://www.bioethicsanddisability.org/nanotechnology.html Bioethics and Disability] Nanotechnology
+
* [http://www.bioethicsanddisability.org/nanotechnology.html Bioethics and Disability] Nanotechnology
−
*[http://www.nanotechwatch.org NanotechWatch.org] Nanotechnology news: the hype and the reality of this emerging technology
+
* [http://www.nanotechwatch.org NanotechWatch.org] Nanotechnology news: the hype and the reality of this emerging technology
−
*[http://cns.ucsb.edu/index.html CNS-UCSB]  Center for Nanotechnology in Society
+
* [http://cns.ucsb.edu/index.html CNS-UCSB]  Center for Nanotechnology in Society
 +
* [http://nano.eserver.org/ Societal Dynamics of Nanoscale Science and Technology]
 +
* [http://www.nanozone.org/ Nanozone] Nanotechnology education for ages 8-14 and the public
 +
* [http://nano.foe.org.au/ Nanotechnology Project] - Friends of the Earth
 +
* Friends of the Earth, "[http://nano.foe.org.au/ Nanotechnology Project] — Criticism of nanotechnology.
  
−
====Other====
+
== References ==
−
* [http://www.nanodaddy.com Latest Nanotechnology Research News and Careers]
 
−
* [http://www.ntcgmbh.com Research Results used in Industrial Applications ]
 
−
* [http://www.nanotechnology.com/ Nanotechnology.com] News, information, and exclusive articles
 
−
* [http://www.nano-map.de Nano-map.de] - Nano-map is a graphical tool for the visualization of the regional distribution of relevant nanotechnology institutions in Germany including major enterprises, SMEs, networks, research centers, university institutes, funding agencies, technology transfer and financing institutions.
 
−
* [http://www.nanowerk.com/ Nanowerk] - A free database to research 800 nanomaterials from over 75 manufacturers
 
−
* [http://www.foresight.org/ Foresight Institute]
 
−
* [http://icon.rice.edu/ International Council on Nanotechnology]
 
−
* [http://www.MolecularAssembler.com Molecular Assembler website]
 
−
* [http://www.nanoindian.com Nanotechnology in India]
 
−
* [http://www.nanobuildings.com/ NanoBuildings - Buildings for Advanced Technology Workshops]
 
−
* [http://www.nano.gov/ National Nanotechnology Initiative]
 
−
* [http://nanoDiamond.info/ NanoDiamond] atomic level design of a very high strength-to-weight ratio material
 
−
* [http://www.nanotec2005.com/ Nanotec Congress in Brazil]
 
−
* [http://nprl.bham.ac.uk/ UK research]
 
−
* [http://www.wise-nano.org Wise-Nano] A Wiki project, initiated by the [http://crnano.org/ Center for Responsible Nanotechnology] and devoted to [[Molecular engineering|Molecular Manufacturing]]
 
−
*[http://www.etcgroup.org/article.asp?newsid=375 The Big Down] - The first Civil Society Critique of Nanoscale technologies from [http://www.etcgroup.org ETC Group]
 
−
* [[PNAS]] supplement: [http://www.pnas.org/content/vol99/suppl_2/ ''Nanoscience: Underlying Physical Concepts and Phenomena'']
 
−
* [http://www.nanomedicine.com Medical nanorobotics textbooks online]
 
−
* [http://www.zyvex.com/nano/ Nanotechnology by Dr.Ralph Merkle]
 
−
* [http://www.nanoindustries.com/ Nanotechnology Industries]
 
−
* [http://www.knhproductions.ca/nisnano/ Documentary on Nanotechnology]
 
−
* [http://www.human-evolution.org/nano.php Nanotechnology: Is it Real?]
 
−
* [http://www.physorg.com/news3415.html Plasmons (Physorg)]
 
−
* [http://www.nanocrete.com nanotechnology applied to concrete manufacturing]
 
−
* [http://whatsnextnetwork.com/technology/index.php/2005/06/22/nanoparticles_transport_cancer_killing_d Nanotechnology & Cancer Cures]
 
−
* [http://www.nanotechnologybasics.com/ Nanotechnology Basics]
 
−
* [http://www.microtec-d.com Nanomaterials used in BioMEMS]
 
−
* [http://www.nano-biology.net Nanomedicine Resources - labs, literature, jobs, news, discussion - academic focus]
 
−
* [http://www.micronit.com Nanofluidics]
 
−
* [http://www.michaelmarshallsmith.com/books.htm#wymi Short Story, "Hell Hath Enlarged Herself", by Michael Marshall Smith.]  Deals with possible worst-case outcome of nanotechnology.
 
  
−
====Scientists in the Field====
+
* {{cite book|author=Daniel J. Shanefield|year=1996|title=Organic Additives And Ceramic Processing|publisher=Kluwer Academic Publishers|id=ISBN 0792397657[http://www.criandoofertas.com.br .]}}
  
−
Dr. David G. Grier, of New York University, has developed a method of rapidly modulating laser beams via a dynamic [[spatial light modulator]] (SLM) in the form of a phase only hologram. (http://www.physics.nyu.edu/grierlab/)[[robots]]
+
* [http://www.merid.org/NDN/ Meridian Institute's Nanotechnology and Development News]
−
 
 
−
== References ==
 
−
 
 
−
* {{Book reference|Author=Daniel J. Shanefield|Year=1996|Title=Organic Additives And Ceramic Processing|Publisher=Kluwer Academic Publishers|ID=ISBN 0792397657[http://www.criandoofertas.com.br .]}}
 
  
 
* [http://www.nanotechproject.org/ Project on Emerging Nanotechnologies]
 
* [http://www.nanotechproject.org/ Project on Emerging Nanotechnologies]
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* [http://www.nanobusiness.org/ NanoBusiness Alliance]
 
* [http://www.nanobusiness.org/ NanoBusiness Alliance]
  
−
* {{Book reference|Author=Hunt, Geoffrey & Mehta, Michael (eds)|Year=2006|Title=Nanotechnology: Risk Ethics, & Law|Publisher=Earthscan, London| date:2006]}}
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* {{cite book|author=Hunt, Geoffrey & Mehta, Michael (eds)|year=2006|title=Nanotechnology: Risk Ethics, & Law|publisher=Earthscan, London| date:2006]}}
  
  
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Revision as of 01:14, 16 May 2006

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
Wikibooks has more about this subject:
  • 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

Laboratories

Nanotechnology and society

References
ISBN links support NWE through referral fees

  • Daniel J. Shanefield (1996). Organic Additives And Ceramic Processing. Kluwer Academic Publishers. ISBN 0792397657.. 
  • Hunt, Geoffrey & Mehta, Michael (eds) (2006). Nanotechnology: Risk Ethics, & Law. Earthscan, London. 


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