Nanotechnology: Difference between revisions

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{{Short description|Technology with features near one nanometer}}

'''Nanotechnology''' is technology on the scale of the [[nanometer]]. Physically, this relates to sizes of only a few [[atom|atoms]]' width. Implementing nanotechnology in its fullest sense would require the ability to directly manipulate atoms or [[molecule|molecules]]. It is sometimes called ''Molecular nanotechnology'' to distinguish it from [[MEMS]].

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{{for-multi|the materials science journal|Nanotechnology (journal)|other uses of "Nanotech"|Nanotech (disambiguation)}}

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[[File:Fullerene Nanogears - GPN-2000-001535.jpg|thumb|300px|Fullerene nanogears]]

{{Nanotechnology}}

'''Nanotechnology''' is the manipulation of matter with at least one dimension sized from 1 to 100 [[nanometers]] (nm). At this scale, commonly known as the '''nanoscale''', [[surface area]] and [[quantum mechanical]] effects become important in describing properties of matter. This definition of nanotechnology includes all types of research and technologies that deal with these special properties. It is common to see the plural form "nanotechnologies" as well as "nanoscale technologies" to refer to research and applications whose common trait is scale.<ref name="Engines1">{{cite book| vauthors = Drexler KE |title=Engines of Creation: The Coming Era of Nanotechnology |url= https://archive.org/details/enginesofcreatio00drex |oclc=12752328 |url-access=registration |year=1986 |publisher=Doubleday|isbn=978-0-385-19973-5}}</ref> An earlier understanding of nanotechnology referred to the particular technological goal of precisely manipulating atoms and molecules for fabricating macroscale products, now referred to as [[molecular nanotechnology]].<ref name="Nanotsystems">{{cite book| vauthors = Drexler KE |title=Nanosystems: Molecular Machinery, Manufacturing, and Computation|url=https://books.google.com/books?id=F6BRAAAAMAAJ|oclc=26503231|year=1992|publisher=Wiley |isbn=978-0-471-57547-4}}</ref>

[[Ralph Merkle]] has compared today's [[chemistry]] to an attempt to build interesting [[Lego]] brick constructions while wearing [[boxing]] gloves. Because we currently have no tools that allow us to place a particular [[atom]] in a particular place (so that it bonds in a predictable way with another particular atom), we must work with statistically large numbers of atoms. As a result, when we cause a particular chemical reaction, we frequently get a mix of several different product species. The reaction is often followed by a physical filtering process to extract the species we actually wanted, with the other species discarded as waste. Nanotechnology could therefore offer much cleaner manufacturing processes than are available with today's bulk technology.

Nanotechnology defined by scale includes fields of science such as [[surface science]], [[organic chemistry]], [[molecular biology]], [[semiconductor physics]], [[energy storage]],<ref>{{cite journal| vauthors = Hubler A |s2cid=6994736|title=Digital quantum batteries: Energy and information storage in nanovacuum tube arrays|journal=Complexity|pages=48–55|volume=15|issue=5|date=2010|doi=10.1002/cplx.20306|doi-access=free| issn = 1076-2787}}</ref><ref>{{cite journal| vauthors = Shinn E |s2cid=35742708|title=Nuclear energy conversion with stacks of graphene nanocapacitors|journal=Complexity|date=2012|doi=10.1002/cplx.21427|bibcode=2013Cmplx..18c..24S|volume=18|issue=3|pages=24–27}}</ref> [[engineering]],<ref>{{cite book | vauthors = Elishakoff I, Dujat K, Muscolino G, Bucas S, Natsuki T, Wang CM, Pentaras D, Versaci C, Storch J, Challamel N, Zhang Y | title = Carbon Nanotubes and Nano Sensors: Vibrations, Buckling, and Ballistic Impact | publisher = John Wiley & Sons | date = March 2013 | isbn = 978-1-84821-345-6 }}</ref> [[microfabrication]],<ref>{{cite journal| vauthors = Lyon D, Hubler A |s2cid=709782|title=Gap size dependence of the dielectric strength in nano vacuum gaps|journal=[[IEEE Transactions on Dielectrics and Electrical Insulation]]|date=2013|doi=10.1109/TDEI.2013.6571470|volume=20|issue=4|pages=1467–71}}</ref> and [[molecular engineering]].<ref>{{cite journal | vauthors = Saini R, Saini S, Sharma S | title = Nanotechnology: the future medicine | journal = Journal of Cutaneous and Aesthetic Surgery | volume = 3 | issue = 1 | pages = 32–33 | date = January 2010 | pmid = 20606992 | pmc = 2890134 | doi = 10.4103/0974-2077.63301 | doi-access = free }}</ref> The associated research and applications range from extensions of conventional [[Semiconductor device|device physics]] to [[molecular self-assembly]],<ref>{{cite journal | vauthors = Belkin A, Hubler A, Bezryadin A | title = Self-assembled wiggling nano-structures and the principle of maximum entropy production | journal = Scientific Reports | volume = 5 | pages = 8323 | date = February 2015 | pmid = 25662746 | pmc = 4321171 | doi = 10.1038/srep08323 | bibcode = 2015NatSR...5.8323B }}</ref> from developing [[Nanomaterial|new materials]] with dimensions on the nanoscale to [[Molecular nanotechnology|direct control of matter on the atomic scale]].

The first mention of nanotechnology (not yet using that name) was in a talk given by [[Richard Feynman]] in 1959, entitled ''There's [[Plenty of Room at the Bottom]]''. Feynman suggested a means to develop the ability to manipulate atoms and molecules directly, by developing a set of one-tenth-scale machine tools analogous to those found in any machine shop. These small tools would be used to develop and operate a next generation of one-hundredth-scale machine tools, and so forth. As the sizes get smaller, it would be necessary to redesign some tools because the relative strength of various forces would change. Gravity would become less important, surface tension would become more important, [[van der Waals]] attraction would become important, etc. Feynman mentioned these scaling issues during his talk. The feasibility of his proposal has never been effectively refuted.

Nanotechnology may be able to create new materials and devices with diverse [[List of nanotechnology applications|applications]], such as in [[nanomedicine]], [[nanoelectronics]], [[Nanotechnology in agriculture|agricultural sectors]],{{cn|date=February 2025}} [[biomaterial]]s energy production, and consumer products. However, nanotechnology raises issues, including concerns about the [[Nanotoxicology|toxicity]] and environmental impact of nanomaterials,<ref>{{cite journal | vauthors = Buzea C, Pacheco II, Robbie K | title = Nanomaterials and nanoparticles: sources and toxicity | journal = Biointerphases | volume = 2 | issue = 4 | pages = MR17–MR71 | date = December 2007 | pmid = 20419892 | doi = 10.1116/1.2815690 | arxiv = 0801.3280 | s2cid = 35457219 }}</ref> and their potential effects on global economics, as well as various [[Grey goo|doomsday scenarios]]. These concerns have led to a debate among advocacy groups and governments on whether special [[regulation of nanotechnology]] is warranted.

The term ''nanotechnology'' was first used by [[K. Eric Drexler]] in his book [[Engines of creation|Engines of Creation: The Coming Era of Nanotechnology]] (text available online [http://www.foresight.org/EOC/]) ISBN 0-385-19973-2. In the fourth chapter, Drexler introduces [[self-replication]] (see also [[Von Neumann machine]]), another powerful premise of nanotechnology. Cells build copies of themselves in order to reproduce, and human-designed molecular [[robot]]s could do the same thing. This would mean that after the enormous research expense of designing and constructing the first molecular robot capable of self-replication, the next trillion robots would cost no more than an equal mass in [[vegetable]]s.

==Origins==

These same generally capable robots, called ''assemblers'', could then build more special-purpose objects that humans would find directly useful: [[house]]s, [[kitchen]] widgets, [[automobile|cars]], [[furniture]], medical instruments, [[spaceship]]s, etc. Like the assemblers themselves, these products would be extremely cheap by comparison with those produced today. Specifically, the inputs to any such manufacturing process would be raw materials (atoms), [[energy]], design [[software]], and [[time]].

{{Main|History of nanotechnology}}

The concepts that seeded nanotechnology were first discussed in 1959 by physicist [[Richard Feynman]] in his talk ''[[There's Plenty of Room at the Bottom]]'', in which he described the possibility of synthesis via direct manipulation of atoms.

[[File:Comparison of nanomaterials sizes.jpg|thumb|upright=1.8|right|Comparison of nanomaterials sizes]]

Whilst progress has been made in producing ever-smaller [[computer]] [[circuit]]s and [[nanowire]]s, and manipulating individual atoms, constructing real nanomachines is currently well beyond our present capabilities and are generally believed to be at least decades away. Many doubt that controllable self-replicating [[nanobot]]s are possible at all, citing the possibility of [[mutation]]s removing any control and favouring reproduction of the mutant pathogenic variations. Advocates counter that [[bacteria]] are designed to mutate, and nanobot mutation can be prevented by common error-correcting techniques used in computers today. Research in this area has included the development of simulation software, such as [[NanoCAD]].

The term "nano-technology" was first used by [[Norio Taniguchi]] in 1974, though it was not widely known. Inspired by Feynman's concepts, [[K. Eric Drexler]] used the term "nanotechnology" in his 1986 book ''[[Engines of creation|Engines of Creation: The Coming Era of Nanotechnology]]'', which achieved popular success and helped thrust nanotechnology into the public sphere.<ref>{{Cite book |last=Ford |first=Martin |authorlink=Marin Ford |year=2018 |title=[[Rise of the Robots|Rise of the Robots: Technology and the threat of a jobless future]] |publisher=[[Basic Books]] |isbn=978-0-465-09753-1 |page=242 |quote=He coined the term "nanotechnology" and wrote towo books on the subject. The first, Engines of Creation: The Coming Era of Nanotechnology, published in 1986, achieved popular success and was the primary force that thrust nanotechnology into the public sphere.}}</ref> In it he proposed the idea of a nanoscale "assembler" that would be able to build a copy of itself and of other items of arbitrary complexity with atom-level control. Also in 1986, Drexler co-founded [[The Foresight Institute]] to increase public awareness and understanding of nanotechnology concepts and implications.

Despite its current infeasability, there has been much speculation about the impact of nanotechnology on [[economics]] and [[law]]. Some believe that [[money]] would cease to be of use and [[taxation]] would cease to be feasible. Others conjecture that nanotechnology would elicit a strong public-opinion backlash, as has occurred recently around genetically modified plants and the prospect of human [[cloning]]. Whatever the exact effects, nanotechnology is likely to upset existing economic structures, as it changes the relative [[scarcity]] of various goods and services.

The emergence of nanotechnology as a field in the 1980s occurred through the convergence of Drexler's theoretical and public work, which developed and popularized a conceptual framework, and experimental advances that drew additional attention to the prospects{{cn|date=August 2025}}. In the 1980s, two breakthroughs helped to spark the growth of nanotechnology. First, the invention of the [[scanning tunneling microscope]] in 1981 enabled visualization of individual atoms and bonds, and was successfully used to manipulate individual atoms in 1989. The microscope's developers [[Gerd Binnig]] and [[Heinrich Rohrer]] at [[IBM Zurich Research Laboratory]] received a [[Nobel Prize in Physics]] in 1986.<ref name="Binnig">{{Cite journal| vauthors = Binnig G, Rohrer H |title=Scanning tunneling microscopy|journal=IBM Journal of Research and Development|volume=30|issue=4|year=1986|pages=355–369 |doi=10.1147/rd.441.0279}}</ref><ref>{{cite web|title=Press Release: the 1986 Nobel Prize in Physics|url=http://nobelprize.org/nobel_prizes/physics/laureates/1986/press.html|publisher=Nobelprize.org|access-date=12 May 2011|date=15 October 1986|url-status=live|archive-url=https://web.archive.org/web/20110605005907/http://nobelprize.org/nobel_prizes/physics/laureates/1986/press.html|archive-date=5 June 2011}}</ref> Binnig, [[Calvin F. Quate|Quate]] and Gerber also invented the analogous [[atomic force microscopy|atomic force microscope]] that year.

It has been suggested that there will still be a need for money, in the form of unforgeable [[digital cash]], even when advanced nanotechnology exists. It might be useful in markets for those goods and services that are unique, or for which only a finite amount exists in the solar system. These might include: matter, energy, information, real estate, design services, entertainment services, legal services, fame, political power, or the attention of other people to your political/religious/philisophical message. Some people have claimed that no matter how good virtual reality gets, there will always be a strong interest in obtaining limited resources, such as a chance to talk to the real president of a major country, or owning part of the real [[Jerusalem]], or having a famous celebrity say nice things about you in a digitally-signed document, or gaining the mining rights to the larger near-earth asteroids. Demand will always exceed supply for some things.

[[File:C60 Molecule.svg|thumb|upright=0.8|left|[[Buckminsterfullerene]] C₆₀, also known as the [[buckyball]], is a representative member of the [[Allotropes of carbon|carbon structures]] known as [[fullerene]]s. Members of the fullerene family are a major subject of research falling under the nanotechnology umbrella.]]

Of course, nanotechnology is not without its risks. In addition to enabling the development of much cheaper and more destructive conventional [[weapon]]s, nanotechnology also offers the possibility of weapons that operate by self-replication, as [[virus (biology)|virus]]es and [[cancer]] cells do when attacking the human body. There is general agreement that self-replication should be permitted only very controlled conditions.

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| footer = Harry Kroto (left) won the 1996 Nobel Prize in Chemistry along with Richard Smalley (right) and Robert Curl for their 1985 discovery of [[buckminsterfullerene]], while Sumio Iijima (middle) won the inaugural 2008 [[Kavli Prize]] in Nanoscience for his 1991 discovery of [[carbon nanotubes]].

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Second, [[fullerenes]] (buckyballs) were discovered in 1985 by [[Harry Kroto]], [[Richard Smalley]], and [[Robert Curl]], who together won the 1996 [[Nobel Prize in Chemistry]].<ref>{{Cite journal | vauthors = Kroto HW, Heath JR, O'Brien SC, Curl RF, Smalley RE |doi=10.1038/318162a0|title=C₆₀: Buckminsterfullerene|journal=Nature|volume=318|issue=6042|pages=162–3 |year=1985 |s2cid=4314237|bibcode=1985Natur.318..162K}}</ref><ref>{{cite journal | vauthors = Adams WW, Baughman RH | title = Retrospective: Richard E. Smalley (1943-2005) | journal = Science | volume = 310 | issue = 5756 | pages = 1916 | date = December 2005 | pmid = 16373566 | doi = 10.1126/science.1122120 | doi-access = free }}</ref> C₆₀ was not initially described as nanotechnology; the term was used regarding subsequent work with related [[carbon nanotube]]s (sometimes called [[graphene]] tubes or Bucky tubes) which suggested potential applications for nanoscale electronics and devices. The discovery of [[carbon nanotubes]] is attributed to [[Sumio Iijima]] of [[NEC]] in 1991,<ref name="carbon">{{Cite journal|title=Who should be given the credit for the discovery of carbon nanotubes?|doi=10.1016/j.carbon.2006.03.019| vauthors = Monthioux M, Kuznetsov V |journal=[[Carbon (journal)|Carbon]]|volume=44|year=2006|url=http://www.cemes.fr/fichpdf/GuestEditorial.pdf|pages=1621–3|issue=9|bibcode=2006Carbo..44.1621M|access-date=2019-07-09|archive-date=2009-09-29|archive-url=https://web.archive.org/web/20090929073818/http://www.cemes.fr/fichpdf/GuestEditorial.pdf|url-status=dead}}</ref> for which Iijima won the inaugural 2008 [[Kavli Prize]] in Nanoscience.

In light of these dangers, the [[Foresight Institute]] (founded by Drexler to prepare for the arrival of future technologies) has drafted a set of guidelines [http://www.foresight.org/guidelines/current.html] for the ethical development of nanotechnology.

In the early 2000s, the field garnered increased scientific, political, and commercial attention that led to both controversy and progress. Controversies emerged regarding the definitions and potential implications of nanotechnologies, exemplified by the [[Royal Society]]'s report on nanotechnology.<ref name="royalsociety">{{cite web |date=July 2004 |title=Nanoscience and nanotechnologies: opportunities and uncertainties |url=http://www.nanotec.org.uk/finalReport.htm |url-status=dead |archive-url=https://web.archive.org/web/20110526060835/http://www.nanotec.org.uk/finalReport.htm |archive-date=26 May 2011 |access-date=13 May 2011 |publisher=Royal Society and Royal Academy of Engineering |page=xiii}}</ref> Challenges were raised regarding the feasibility of applications envisioned by advocates of molecular nanotechnology, which culminated in a public debate between Drexler and Smalley in 2001 and 2003.<ref name="counterpoint">{{cite journal|url=http://pubs.acs.org/cen/coverstory/8148/8148counterpoint.html|title=Nanotechnology: Drexler and Smalley make the case for and against 'molecular assemblers'|journal=Chemical & Engineering News|volume=81|issue=48|pages=37–42|date=1 December 2003|access-date=9 May 2010|doi=10.1021/cen-v081n036.p037|doi-access=free }}</ref>

Drexler and others have extended the ideas of nanotechnology with two more books, ''Unbounding the Future: the Nanotechnology Revolution'' [http://www.foresight.org/UTF/Unbound_LBW/] and ''Nanosystems: molecular machinery, manufacturing, and computation'' [http://www.zyvex.com/nanotech/nanosystems.html]. ''Unbounding the Future'' is an easy-to-read book that introduces the ideas of nanotechnology in a not-too-technical way, and ''Nanosystems'' is an in-depth analysis of several possible nanotechnological devices, with thorough [[scientific method|scientific analyses]] of their feasibility and performance. Another notable work in the same vein is ''[[Nanomedicine]]'' by [[Robert Freitas]]. Nanotechnology has also become a prominent theme in [[science fiction]] [http://www.geocities.com/asnapier/nano/n-sf/], for example with the [[Borg]] in [[Star Trek]], and [[Neal Stephenson]]'s book [[Neal Stephenson/The Diamond Age|The Diamond Age]].

Meanwhile, commercial products based on advancements in nanoscale technologies began emerging. These products were limited to bulk applications of [[nanomaterials]] and did not involve atomic control of matter. Some examples include the [[Silver Nano]] platform for using [[silver nanoparticles]] as an [[Bactericide|antibacterial agent]], [[nanoparticle]]-based sunscreens, [[Carbon fibers|carbon fiber]] strengthening using [[Silicon dioxide|silica]] nanoparticles, and [[Carbon nanotube|carbon nanotubes]] for stain-resistant textiles.<ref name="americanelements">{{cite web|title=Nanotechnology Information Center: Properties, Applications, Research, and Safety Guidelines|url=http://www.americanelements.com/nanomaterials-nanoparticles-nanotechnology.html|publisher=[[American Elements]]|access-date=13 May 2011|url-status=live|archive-url=https://web.archive.org/web/20141226011154/http://www.americanelements.com/nanomaterials-nanoparticles-nanotechnology.html|archive-date=26 December 2014}}</ref><ref name="emergingnano">{{cite web|year=2008|url=http://www.nanotechproject.org/inventories/consumer/analysis_draft/|publisher=The Project on Emerging Nanotechnologies|title=Analysis: This is the first publicly available on-line inventory of nanotechnology-based consumer products|access-date=13 May 2011|url-status=live|archive-url=https://web.archive.org/web/20110505011238/http://www.nanotechproject.org/inventories/consumer/analysis_draft/|archive-date=5 May 2011 }}</ref>

Governments moved to promote and [[Funding of science|fund research]] into nanotechnology, such as American the [[National Nanotechnology Initiative]], which formalized a size-based definition of nanotechnology and established research funding, and in Europe via the European [[Framework Programmes for Research and Technological Development]].

By the mid-2000s scientific attention began to flourish. Nanotechnology roadmaps centered on atomically precise manipulation of matter and discussed existing and projected capabilities, goals, and applications.<ref name="PNRoadmap">{{cite web |title=Productive Nanosystems Technology Roadmap |url=http://www.productivenanosystems.com/docs/Nanotech_Roadmap_2007_main.pdf |url-status=live |archive-url= https://web.archive.org/web/20130908014630/http://www.productivenanosystems.com/docs/Nanotech_Roadmap_2007_main.pdf |archive-date=2013-09-08}}</ref><ref name="NASAroadmap">{{cite web |title=NASA Draft Nanotechnology Roadmap |url=http://www.nasa.gov/pdf/501325main_TA10-Nanotech-DRAFT-Nov2010-A.pdf |url-status=live |archive-url=https://web.archive.org/web/20130122114146/http://www.nasa.gov/pdf/501325main_TA10-Nanotech-DRAFT-Nov2010-A.pdf |archive-date=2013-01-22}}</ref>

==Fundamental concepts==

Nanotechnology is the science and engineering of functional systems at the molecular scale. In its original sense, nanotechnology refers to the projected ability to construct items from the bottom up making complete, high-performance products.

One [[nanometer]] (nm) is one billionth, or 10⁻⁹, of a meter. By comparison, typical carbon–carbon [[bond length]]s, or the spacing between these [[atom]]s in a [[molecule]], are in the range {{nowrap|0.12–0.15 nm}}, and [[DNA]]'s diameter is around 2&nbsp;nm. On the other hand, the smallest [[cell (biology)|cellular]] life forms, the bacteria of the genus ''[[Mycoplasma]]'', are around 200&nbsp;nm in length. By convention, nanotechnology is taken as the scale range {{nowrap|1 to 100 nm}}, following the definition used by the American [[National Nanotechnology Initiative]]. The lower limit is set by the size of atoms (hydrogen has the smallest atoms, which have an approximately ,25&nbsp;nm [[kinetic diameter]]). The upper limit is more or less arbitrary, but is around the size below which phenomena not observed in larger structures start to become apparent and can be made use of.<ref>{{cite book| vauthors = Allhoff F, Lin P, Moore D |title=What is nanotechnology and why does it matter?: from science to ethics|pages=3–5|publisher=Wiley |year=2010|isbn=978-1-4051-7545-6 |oclc=830161740}}</ref> These phenomena make nanotechnology distinct from devices that are merely miniaturized versions of an equivalent [[macroscopic scale|macroscopic]] device; such devices are on a larger scale and come under the description of [[microtechnology]].<ref>{{cite book| vauthors = Prasad SK |title=Modern Concepts in Nanotechnology|pages=31–32|publisher=Discovery Publishing House|year=2008|isbn=978-81-8356-296-6 |oclc=277278905}}</ref>

To put that scale in another context, the comparative size of a nanometer to a meter is the same as that of a marble to the size of the earth.<ref name="NationalG">{{cite journal| vauthors = Kahn J | title=Nanotechnology|journal=National Geographic|volume=2006|issue=June|pages=98–119|year=2006}}</ref>

Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecular components which [[self-assembly|assemble themselves]] chemically by principles of [[molecular recognition]].<ref name="ReferenceA">{{cite journal | vauthors = Kralj S, Makovec D | title = Magnetic Assembly of Superparamagnetic Iron Oxide Nanoparticle Clusters into Nanochains and Nanobundles | journal = ACS Nano | volume = 9 | issue = 10 | pages = 9700–7 | date = October 2015 | pmid = 26394039 | doi = 10.1021/acsnano.5b02328 }}</ref> In the "top-down" approach, nano-objects are constructed from larger entities without atomic-level control.<ref>{{cite journal|journal=Nature Nanotechnology| vauthors = Rodgers P |year=2006|title=Nanoelectronics: Single file|doi=10.1038/nnano.2006.5|doi-access=free}}</ref>

Areas of physics such as [[nanoelectronics]], [[nanomechanics]], [[nanophotonics]] and [[nanoionics]] have evolved to provide nanotechnology's scientific foundation.

===Larger to smaller: a materials perspective===

[[File:Atomic resolution Au100.JPG|right|thumb|Image of [[Surface reconstruction|reconstruction]] on a clean [[Gold]]([[Miller index|100]]) surface, as visualized using [[scanning tunneling microscopy]]. The positions of the individual atoms composing the surface are visible.]]

{{main|Nanomaterials}}

Several phenomena become pronounced as system size. These include [[statistical mechanics|statistical mechanical]] effects, as well as [[Quantum mechanics|quantum mechanical]] effects, for example, the "[[quantum]] size effect" in which the electronic properties of solids alter along with reductions in particle size. Such effects do not apply at macro or micro dimensions. However, quantum effects can become significant when nanometer scales. Additionally, physical (mechanical, electrical, optical, etc.) properties change versus macroscopic systems. One example is the increase in surface area to volume ratio altering mechanical, thermal, and catalytic properties of materials. [[Diffusion]] and reactions can be different as well. Systems with fast ion transport are referred to as nanoionics. The mechanical properties of nanosystems are of interest in research.

===Simple to complex: a molecular perspective===

{{Main|Molecular self-assembly}}

Modern [[chemical synthesis|synthetic chemistry]] can prepare small molecules of almost any structure. These methods are used to manufacture a wide variety of useful chemicals such as [[drug|pharmaceuticals]] or commercial [[polymer]]s. This ability raises the question of extending this kind of control to the next-larger level, seeking methods to assemble single molecules into [[supramolecular assembly|supramolecular assemblies]] consisting of many molecules arranged in a well-defined manner.

These approaches utilize the concepts of molecular [[self-assembly]] and/or [[supramolecular chemistry]] to automatically arrange themselves into a useful conformation through a [[Top-down and bottom-up#Nanotechnology|bottom-up]] approach. The concept of [[molecular recognition]] is important: molecules can be designed so that a specific configuration or arrangement is favored due to [[Noncovalent bonding|non-covalent]] [[intermolecular force]]s. The Watson–Crick [[base pair|basepairing]] rules are a direct result of this, as is the specificity of an [[enzyme]] targeting a single [[substrate (biochemistry)|substrate]], or the specific [[protein folding|folding of a protein]]. Thus, components can be designed to be complementary and mutually attractive so that they make a more complex and useful whole.

Such bottom-up approaches should be capable of producing devices in parallel and be much cheaper than top-down methods, but could potentially be overwhelmed as the size and complexity of the desired assembly increases. Most useful structures require complex and thermodynamically unlikely arrangements of atoms. Nevertheless, many examples of self-assembly based on molecular recognition in exist in [[biology]], most notably Watson–Crick basepairing and enzyme-substrate interactions.

===Molecular nanotechnology: a long-term view===

{{Main|Molecular nanotechnology}}

[[Image:Protein translation.gif|thumb|300px|[[Ribosome]] translating [[DNA]] is a [[biological machine]] functioning as a [[molecular assembler]]. [[Protein ___domain dynamics]] can now be seen by [[neutron spin echo]] spectroscopy]]

Molecular nanotechnology, sometimes called molecular manufacturing, concerns engineered nanosystems (nanoscale machines) operating on the molecular scale. Molecular nanotechnology is especially associated with [[molecular assembler]]s, machines that can produce a desired structure or device atom-by-atom using the principles of [[mechanosynthesis]]. Manufacturing in the context of [[productive nanosystems]] is not related to conventional technologies used to manufacture nanomaterials such as carbon nanotubes and nanoparticles.

When Drexler independently coined and popularized the term "nanotechnology", he envisioned manufacturing technology based on [[molecular machine]] systems. The premise was that molecular-scale biological analogies of traditional machine components demonstrated molecular machines were possible: biology was full of examples of sophisticated, [[stochastic]]ally optimized [[Molecular machine#Biological|biological machines]].

Drexler and other researchers<ref>{{cite web| vauthors = Phoenix C |date=March 2005|url=http://www.crnano.org/developing.htm|title=Nanotechnology: Developing Molecular Manufacturing|archive-url=https://web.archive.org/web/20200601095107/http://www.crnano.org/developing.htm|archive-date=2020-06-01}}. crnano.org</ref> have proposed that advanced nanotechnology ultimately could be based on mechanical engineering principles, namely, a manufacturing technology based on the mechanical functionality of these components (such as gears, bearings, motors, and structural members) that would enable programmable, positional assembly to atomic specification.<ref>{{cite web|url=http://www.imm.org/PNAS.html|title=Some papers by K. Eric Drexler|work=imm.org|url-status=live|archive-url=https://web.archive.org/web/20060411075149/http://www.imm.org/PNAS.html|archive-date=2006-04-11}}</ref> The physics and engineering performance of exemplar designs were analyzed in Drexler's book ''Nanosystems: Molecular Machinery, Manufacturing, and Computation''.<ref name=Nanotsystems />

In general, assembling devices on the atomic scale requires positioning atoms on other atoms of comparable size and stickiness. [[Carlo Montemagno]]'s view is that future nanosystems will be hybrids of silicon technology and biological molecular machines.<ref>{{cite web |title=Carlo Montemagno, Ph.D. |url=http://www.cnsi.ucla.edu/institution/personnel?personnel%5fid=105488 |archive-url=https://web.archive.org/web/20141008065938/http://faculty.cnsi.ucla.edu/institution/personnel?personnel%5fid=105488 |archive-date=2014-10-08 |website=California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA)}}</ref> [[Richard Smalley]] argued that mechanosynthesis was impossible due to difficulties in mechanically manipulating individual molecules.<ref>{{Cite journal |last=Smalley |first=Richard E. |date=2001 |title=Of Chemistry, Love and Nanobots |url=https://www.jstor.org/stable/26059339 |journal=Scientific American |volume=285 |issue=3 |pages=76–77 |doi=10.1038/scientificamerican0901-76 |jstor=26059339 |pmid=11524973 |bibcode=2001SciAm.285c..76S |issn=0036-8733}}</ref>

This led to an exchange of letters in the [[American Chemical Society|ACS]] publication [[Chemical & Engineering News]] in 2003.<ref>{{cite journal | vauthors = Baum R |url=http://pubs.acs.org/cen/coverstory/8148/8148counterpoint.html|title=Cover Story – Nanotechnology|date=December 1, 2003|volume=81|issue=48|journal=Chemical and Engineering News|pages=37–42}}</ref> Though biology clearly demonstrates that molecular machines are possible, non-biological molecular machines remained in their infancy. [[Alex Zettl]] and colleagues at Lawrence Berkeley Laboratories and UC Berkeley<ref>{{cite web|url=http://research.physics.berkeley.edu/zettl/|archive-url=https://web.archive.org/web/20151008062820/http://research.physics.berkeley.edu/zettl/|archive-date=2015-10-08|title=Zettl Research Group |publisher=Department of Physics, University of California, Berkeley}}</ref> constructed at least three molecular devices whose motion is controlled via changing voltage: a nanotube [[nanomotor]], a molecular actuator,<ref>{{cite journal | vauthors = Regan BC, Aloni S, Jensen K, Ritchie RO, Zettl A | title = Nanocrystal-powered nanomotor | journal = Nano Letters | volume = 5 | issue = 9 | pages = 1730–3 | date = September 2005 | pmid = 16159214 | doi = 10.1021/nl0510659 | url = http://www.physics.berkeley.edu/research/zettl/pdf/312.NanoLett5regan.pdf | url-status = dead | osti = 1017464 | bibcode = 2005NanoL...5.1730R | archive-url = https://web.archive.org/web/20060510143208/http://www.physics.berkeley.edu/research/zettl/pdf/312.NanoLett5regan.pdf | archive-date = 2006-05-10 }}</ref> and a nanoelectromechanical relaxation oscillator.<ref>{{cite journal|url=http://www.lbl.gov/Science-Articles/Archive/sabl/2005/May/Tiniest-Motor.pdf|doi=10.1063/1.1887827|title=Surface-tension-driven nanoelectromechanical relaxation oscillator|year=2005| vauthors = Regan BC, Aloni S, Jensen K, Zettl A |journal=Applied Physics Letters |volume=86 |page=123119 |bibcode=2005ApPhL..86l3119R|issue=12|url-status=live|archive-url=https://web.archive.org/web/20060526193318/http://www.lbl.gov/Science-Articles/Archive/sabl/2005/May/Tiniest-Motor.pdf|archive-date=2006-05-26}}</ref>

Ho and Lee at [[Cornell University]] in 1999 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 bound the CO to the Fe by applying a voltage.<ref>{{Cite journal |last1=Lee |first1=H. J. |last2=Ho |first2=W. |date=1999-11-26 |title=Single-Bond Formation and Characterization with a Scanning Tunneling Microscope |url=https://www.science.org/doi/10.1126/science.286.5445.1719 |journal=Science |language=en |volume=286 |issue=5445 |pages=1719–1722 |doi=10.1126/science.286.5445.1719 |pmid=10576735 |issn=0036-8075|url-access=subscription }}</ref>

==Research==

[[File:Rotaxane cartoon.jpg|thumb|right|Graphical representation of a [[rotaxane]], useful as a [[molecular switch]]]]

[[File:DNA tetrahedron white.png|thumb|right|This DNA [[tetrahedron]]<ref name="Goodman05">{{cite journal | vauthors = Goodman RP, Schaap IA, Tardin CF, Erben CM, Berry RM, Schmidt CF, Turberfield AJ | title = Rapid chiral assembly of rigid DNA building blocks for molecular nanofabrication | journal = Science | volume = 310 | issue = 5754 | pages = 1661–5 | date = December 2005 | pmid = 16339440 | doi = 10.1126/science.1120367 | s2cid = 13678773 | bibcode = 2005Sci...310.1661G }}</ref> is an artificially [[Nucleic acid design|designed]] nanostructure of the type made in the field of [[DNA nanotechnology]]. Each edge of the tetrahedron is a 20 base pair DNA [[Nucleic acid double helix|double helix]], and each vertex is a three-arm junction.]]

[[File:C60 Buckyball.gif|thumb|upright=0.9|Rotating view of C₆₀, one kind of fullerene]]

[[File:Achermann7RED.jpg|thumb|right|This device transfers energy from nano-thin layers of [[quantum well]]s to nanocrystals above them, causing the nanocrystals to emit visible light.<ref>{{cite web |url= http://www.photonicsonline.com/doc.mvc/Wireless-Nanocrystals-Efficiently-Radiate-Vis-0002 |title=Wireless Nanocrystals Efficiently Radiate Visible Light | date = 12 July 2004 | work = Photonics Online |access-date=5 August 2015 |url-status=live|archive-url=https://web.archive.org/web/20121114102922/http://www.photonicsonline.com/doc.mvc/Wireless-Nanocrystals-Efficiently-Radiate-Vis-0002|archive-date=14 November 2012}}</ref>]]

===Nanomaterials===

Many areas of science develop or study materials having unique properties arising from their nanoscale dimensions.<ref>{{cite journal | title = Nanostructured Ceramics in Medical Devices: Applications and Prospects | journal = JOM | volume = 56 | issue = 10 | pages = 38–43 | year = 2004 | doi = 10.1007/s11837-004-0289-x | vauthors = Narayan RJ, Kumta PN, Sfeir C, Lee DH, Choi D, Olton D | s2cid = 137324362 | bibcode = 2004JOM....56j..38N }}</ref>

*[[Interface and colloid science]] produced many materials that may be useful in nanotechnology, such as carbon nanotubes and other [[fullerenes]], and various nanoparticles and [[nanorod]]s. Nanomaterials with fast ion transport are related to nanoionics and nanoelectronics.

*Nanoscale materials can be used for bulk applications; most commercial applications of nanotechnology are of this flavor.

*Progress has been made in using these materials for [[Nanomedicine|medical applications]], including [[tissue engineering]], [[drug delivery]], [[antibacterials]] and [[biosensor]]s.<ref>{{cite journal | vauthors = Cho H, Pinkhassik E, David V, Stuart JM, Hasty KA | title = Detection of early cartilage damage using targeted nanosomes in a post-traumatic osteoarthritis mouse model | journal = Nanomedicine | volume = 11 | issue = 4 | pages = 939–946 | date = May 2015 | pmid = 25680539 | doi = 10.1016/j.nano.2015.01.011 }}</ref><ref>{{cite journal | vauthors = Kerativitayanan P, Carrow JK, Gaharwar AK | title = Nanomaterials for Engineering Stem Cell Responses | journal = Advanced Healthcare Materials | volume = 4 | issue = 11 | pages = 1600–27 | date = August 2015 | pmid = 26010739 | doi = 10.1002/adhm.201500272 | s2cid = 21582516 }}</ref><ref>{{cite book |title=Nanomaterials in tissue engineering : fabrication and applications |date=2013 |publisher=Woodhead Publishing |isbn=978-0-85709-596-1 | veditors = Gaharwar A, Sant S, Hancock M, Hacking S |___location=Oxford |doi=10.1533/9780857097231 |last1=Gaharwar |first1=A. K. |last2=Sant |first2=S. |last3=Hancock |first3=M. J. |last4=Hacking |first4=S. A. }}</ref><ref>{{cite journal | vauthors = Gaharwar AK, Peppas NA, Khademhosseini A | title = Nanocomposite hydrogels for biomedical applications | journal = Biotechnology and Bioengineering | volume = 111 | issue = 3 | pages = 441–453 | date = March 2014 | pmid = 24264728 | pmc = 3924876 | doi = 10.1002/bit.25160 }}</ref><ref>{{cite journal | vauthors = Eslamian L, Borzabadi-Farahani A, Karimi S, Saadat S, Badiee MR | title = Evaluation of the Shear Bond Strength and Antibacterial Activity of Orthodontic Adhesive Containing Silver Nanoparticle, an In-Vitro Study | journal = Nanomaterials | volume = 10 | issue = 8 | pages = 1466 | date = July 2020 | pmid = 32727028 | pmc = 7466539 | doi = 10.3390/nano10081466 | doi-access = free }}</ref>

*Nanoscale materials such as [[nanopillar]]s are used in [[solar cell]]s.

*Applications incorporating semiconductor [[nanoparticle]]s in products such as display technology, lighting, solar cells and biological imaging; see [[quantum dot]]s.

===Bottom-up approaches===

The bottom-up approach seeks to arrange smaller components into more complex assemblies.

*DNA nanotechnology utilizes Watson–Crick basepairing to construct well-defined structures out of DNA and other [[nucleic acid]]s.

*Approaches from the field of "classical" chemical synthesis (inorganic and [[organic synthesis]]) aim at designing molecules with well-defined shape (e.g. [[bis-peptide]]s<ref name="Levins">{{cite journal|doi=10.1002/chin.200605222|title=The Synthesis of Curved and Linear Structures from a Minimal Set of Monomers|year=2006| vauthors = Levins CG, Schafmeister CE |journal=ChemInform |volume=37 |issue=5 |url= https://figshare.com/articles/The_Synthesis_of_Curved_and_Linear_Structures_from_a_Minimal_Set_of_Monomers/3260635}}</ref>).

*More generally, molecular self-assembly seeks to use concepts of supramolecular chemistry, and molecular recognition in particular, to cause single-molecule components to automatically arrange themselves into some useful conformation.

*[[Atomic force microscopy|Atomic force microscope]] tips can be used as a nanoscale "write head" to deposit a chemical upon a surface in a desired pattern in a process called [[dip-pen nanolithography]]. This technique fits into the larger subfield of [[nanolithography]].

*[[Molecular-beam epitaxy]] allows for bottom-up assemblies of materials, most notably semiconductor materials commonly used in chip and computing applications, stacks, gating, and [[nanowire lasers]].

===Top-down approaches===

These seek to create smaller devices by using larger ones to direct their assembly.

*Many technologies that descended from conventional [[semiconductor fabrication|solid-state silicon methods]] for fabricating [[microprocessor]]s are capable of creating features smaller than 100&nbsp;nm. [[Giant magnetoresistance]]-based hard drives already on the market fit this description,<ref>{{cite web|url=http://www.nano.gov/html/facts/appsprod.html|archive-url=https://web.archive.org/web/20101120234415/http://www.nano.gov/html/facts/appsprod.html|archive-date=2010-11-20|title=Applications/Products|access-date=2007-10-19|publisher=National Nanotechnology Initiative}}</ref> as do [[atomic layer deposition]] (ALD) techniques. [[Peter Grünberg]] and [[Albert Fert]] received the Nobel Prize in Physics in 2007 for their discovery of giant magnetoresistance and contributions to the field of [[spintronics]].<ref>{{cite web|url=http://nobelprize.org/nobel_prizes/physics/laureates/2007/index.html|title=The Nobel Prize in Physics 2007|access-date=2007-10-19|publisher=Nobelprize.org|url-status=live|archive-url=https://web.archive.org/web/20110805062614/http://nobelprize.org/nobel_prizes/physics/laureates/2007/index.html|archive-date=2011-08-05}}</ref>

*Solid-state techniques can be used to create [[nanoelectromechanical systems]] or NEMS, which are related to [[microelectromechanical systems]] or MEMS.

*[[Focused ion beam]]s can directly remove material, or even deposit material when suitable precursor gasses are applied at the same time. For example, this technique is used routinely to create sub-100&nbsp;nm sections of material for analysis in [[transmission electron microscopy]].

*Atomic force microscope tips can be used as a nanoscale "write head" to deposit a resist, which is then followed by an etching process to remove material in a top-down method.

===Functional approaches===

Functional approaches seek to develop useful components without regard to how they might be assembled.

*Magnetic assembly for the synthesis of [[Anisotropy|anisotropic]] [[superparamagnetic]] materials such as magnetic nano chains.<ref name="ReferenceA"/>

*[[Molecular scale electronics]] seeks to develop molecules with useful electronic properties. These could be used as single-molecule components in a nanoelectronic device,<ref>{{cite journal|vauthors=Das S, Gates AJ, Abdu HA, Rose GS, Picconatto CA, Ellenbogen JC|s2cid=13575385|title=Designs for Ultra-Tiny, Special-Purpose Nanoelectronic Circuits|journal=IEEE Transactions on Circuits and Systems I|volume=54|issue=11|pages=2528–40|year=2007|doi=10.1109/TCSI.2007.907864}}</ref> such as [[rotaxane]].

*Synthetic chemical methods can be used to create [[synthetic molecular motor]]s, such as in a so-called [[nanocar]].

===Biomimetic approaches===

* [[Bionics]] or [[biomimicry]] seeks to apply biological methods and systems found in nature to the study and design of engineering systems and modern technology. [[Biomineralization]] is one example of the systems studied.

* [[Bionanotechnology]] is the use of [[biomolecule]]s for applications in nanotechnology, including the use of viruses and lipid assemblies.<ref>{{cite journal | vauthors = Mashaghi S, Jadidi T, Koenderink G, Mashaghi A | title = Lipid nanotechnology | journal = International Journal of Molecular Sciences | volume = 14 | issue = 2 | pages = 4242–82 | date = February 2013 | pmid = 23429269 | pmc = 3588097 | doi = 10.3390/ijms14024242 | doi-access = free | author3-link = Gijsje Koenderink }}</ref><ref>{{cite web | vauthors = Hogan CM | date = May 2010 | veditors = Draggan S | url = http://www.eoearth.org/article/Virus?topic=49496 | title = Virus | archive-url = https://web.archive.org/web/20130513135007/http://www.eoearth.org/article/Virus?topic=49496| archive-date=2013-05-13|website=Encyclopedia of Earth, National Council for Science and the Environment }}</ref> [[Nanocellulose]], a nanopolymer often used for bulk-scale applications, has gained interest owing to its useful properties such as abundance, high aspect ratio, good [[mechanical properties]], [[renewability]], and [[biocompatibility]].<ref>{{cite journal | vauthors = Trache D, Tarchoun AF, Derradji M, Hamidon TS, Masruchin N, Brosse N, Hussin MH | title = Nanocellulose: From Fundamentals to Advanced Applications | journal = Frontiers in Chemistry | volume = 8 | pages = 392 | date = 2020 | pmid = 32435633 | pmc = 7218176 | doi = 10.3389/fchem.2020.00392 | bibcode = 2020FrCh....8..392T | doi-access = free }}</ref>

===Speculative===

These subfields seek to [[Futures studies|anticipate]] what inventions nanotechnology might yield, or attempt to propose an agenda along which inquiry could progress. These often take a big-picture view, with more emphasis on societal implications than engineering details.

*Molecular nanotechnology is a proposed approach that involves manipulating single molecules in finely controlled, deterministic ways. This is more theoretical than the other subfields, and many of its proposed techniques are beyond current capabilities.

*[[Nanorobotics]] considers self-sufficient machines operating at the nanoscale. There are hopes for applying nanorobots in medicine.<ref>{{cite journal | vauthors = Kubik T, Bogunia-Kubik K, Sugisaka M | title = Nanotechnology on duty in medical applications | journal = Current Pharmaceutical Biotechnology | volume = 6 | issue = 1 | pages = 17–33 | date = February 2005 | pmid = 15727553 | doi = 10.2174/1389201053167248 }}</ref><ref>{{cite journal | vauthors = Leary SP, Liu CY, Apuzzo ML | title = Toward the emergence of nanoneurosurgery: part III--nanomedicine: targeted nanotherapy, nanosurgery, and progress toward the realization of nanoneurosurgery | journal = Neurosurgery | volume = 58 | issue = 6 | pages = 1009–26 | date = June 2006 | pmid = 16723880 | doi = 10.1227/01.NEU.0000217016.79256.16 | s2cid = 33235348 }}</ref> Nevertheless, progress on innovative materials and patented methodologies have been demonstrated.<ref>{{cite journal | vauthors = Cavalcanti A, Shirinzadeh B, Freitas RA, Kretly LC | title = Medical nanorobot architecture based on nanobioelectronics | journal = Recent Patents on Nanotechnology | volume = 1 | issue = 1 | pages = 1–10 | year = 2007 | pmid = 19076015 | doi = 10.2174/187221007779814745 | s2cid = 9807497 }}</ref><ref>{{cite journal | vauthors = Boukallel M, Gauthier M, Dauge M, Piat E, Abadie J | title = Smart microrobots for mechanical cell characterization and cell convoying | journal = IEEE Transactions on Bio-Medical Engineering | volume = 54 | issue = 8 | pages = 1536–40 | date = August 2007 | pmid = 17694877 | doi = 10.1109/TBME.2007.891171 | s2cid = 1119820 | url = https://hal.archives-ouvertes.fr/hal-00179481/file/Gauthier-00650-2005-R2-electronic_version.pdf }}</ref>

*Productive nanosystems are "systems of nanosystems" could produce atomically precise parts for other nanosystems, not necessarily using novel nanoscale-emergent properties, but well-understood fundamentals of manufacturing. Because of the discrete (i.e. atomic) nature of matter and the possibility of exponential growth, this stage could form the basis of another industrial revolution. [[Mihail Roco]] proposed four states of nanotechnology that seem to parallel the technical progress of the Industrial Revolution, progressing from passive nanostructures to active nanodevices to complex [[nanomachine]]s and ultimately to productive nanosystems.<ref>{{cite journal | vauthors = Roco MC | title = International Perspective on Government Nanotechnology Funding in 2005. | journal = Journal of Nanoparticle Research | date = December 2005 | volume=7 | issue = 6 |pages=707–712 |url=https://www.nsf.gov/crssprgm/nano/reports/mcr_05-0526_intpersp_nano.pdf |url-status=dead|archive-url=https://web.archive.org/web/20120131175645/http://nsf.gov/crssprgm/nano/reports/mcr_05-0526_intpersp_nano.pdf|archive-date=2012-01-31 |doi=10.1007/s11051-005-3141-5 | bibcode = 2005JNR.....7..707R }}</ref>

*[[Programmable matter]] seeks to design materials whose properties can be easily, reversibly and externally controlled though a fusion of [[information science]] and [[materials science]].

*Due to the popularity and media exposure of the term nanotechnology, the words [[picotechnology]] and [[femtotechnology]] have been coined in analogy to it, although these are used only informally.

===Dimensionality in nanomaterials===

Nanomaterials can be classified in 0D, 1D, 2D and 3D [[nanomaterials]]. Dimensionality plays a major role in determining the characteristic of nanomaterials including [[:wikt:physical|physical]], [[chemical]], and [[biological]] characteristics. With the decrease in dimensionality, an increase in surface-to-volume ratio is observed. This indicates that smaller dimensional [[nanomaterials]] have higher surface area compared to 3D nanomaterials. [[Two dimensional (2D) nanomaterials]] have been extensively investigated for [[electronics|electronic]], [[biomedical]], [[drug delivery]] and [[biosensor]] applications.

==Tools and techniques==

[[File:AFMsetup.jpg|thumb|right|upright=1.35|Typical [[atomic force microscopy|AFM]] setup. A microfabricated [[cantilever]] with a sharp tip is deflected by features on a sample surface, much like in a [[phonograph]] but on a much smaller scale. A [[laser]] beam reflects off the backside of the cantilever into a set of [[photodetector]]s, allowing the deflection to be measured and assembled into an image of the surface.]]

===Scanning microscopes===

The [[atomic force microscopy|atomic force microscope]] (AFM) and the [[Scanning Tunneling Microscope]] (STM) are two versions of scanning probes that are used for nano-scale observation. Other types of [[scanning probe microscopy]] have much higher resolution, since they are not limited by the wavelengths of sound or light.

The tip of a scanning probe can also be used to manipulate nanostructures (positional assembly). [[Feature-oriented scanning]] may be a promising way to implement these nano-scale manipulations via an automatic [[algorithm]].<ref name="feature2004">{{cite journal| vauthors = Lapshin RV |year=2004|title=Feature-oriented scanning methodology for probe microscopy and nanotechnology|journal=Nanotechnology|volume=15|issue=9|pages=1135–51|doi=10.1088/0957-4484/15/9/006|url=http://www.lapshin.fast-page.org/publications.htm#feature2004|format=PDF|bibcode=2004Nanot..15.1135L|s2cid=250913438|url-status=live|archive-url=https://web.archive.org/web/20130909230837/http://www.lapshin.fast-page.org/publications.htm#feature2004|archive-date=2013-09-09}}</ref><ref name="fospm2011">{{cite book| vauthors = Lapshin RV |year=2011|contribution=Feature-oriented scanning probe microscopy|title=Encyclopedia of Nanoscience and Nanotechnology| veditors = Nalwa HS |volume=14|pages=105–115|publisher=American Scientific |isbn=978-1-58883-163-7|url=http://www.lapshin.fast-page.org/publications.htm#fospm2011|format=PDF|url-status=live|archive-url=https://web.archive.org/web/20130909230837/http://www.lapshin.fast-page.org/publications.htm#fospm2011|archive-date=2013-09-09}}</ref> However, this is still a slow process because of low velocity of the microscope.

The top-down approach anticipates nanodevices that must be built piece by piece in stages, much as manufactured items are made. [[Scanning probe microscopy]] is an important technique both for characterization and synthesis. 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. By using, for example, feature-oriented scanning approach, atoms or molecules can be moved around on a surface with scanning probe microscopy techniques.<ref name="feature2004" /><ref name="fospm2011" />

===Lithography===

Various techniques of lithography, such as [[optical lithography]], [[X-ray lithography]], dip pen lithography, [[electron beam lithography]] or [[nanoimprint lithography]] offer top-down fabrication techniques where a bulk material is reduced to a nano-scale pattern.

Another group of nano-technological techniques include those used for fabrication of [[Ion track technology (track etching)|nanotubes]] and [[Ion track technology (track replication)|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 [[copolymer]]s.<ref name="pmid26295171">{{cite journal | vauthors = Kafshgari MH, Voelcker NH, Harding FJ | title = Applications of zero-valent silicon nanostructures in biomedicine | journal = Nanomedicine | volume = 10 | issue = 16 | pages = 2553–71 | year = 2015 | pmid = 26295171 | doi = 10.2217/nnm.15.91 }}</ref>

====Bottom-up====

In contrast, bottom-up techniques build or grow larger structures atom by atom or molecule by molecule. These techniques include chemical synthesis, [[self-assembly]] and positional assembly. [[Dual-polarization interferometry]] is one tool suitable for characterization of self-assembled thin films. Another variation of the bottom-up approach is [[molecular-beam epitaxy]] or MBE. Researchers at [[Bell Telephone Laboratories]] including [[John R. Arthur Jr.|John R. Arthur]]. [[Alfred Y. Cho]], and Art C. Gossard developed and implemented MBE as a research tool in the late 1960s and 1970s. Samples made by MBE were key to the discovery of the [[fractional quantum Hall effect]] for which the [[List of Nobel laureates in Physics|1998 Nobel Prize in Physics]] was awarded. MBE lays down atomically precise layers of atoms and, in the process, build up complex structures. Important for research on semiconductors, MBE is also widely used to make samples and devices for the newly emerging field of [[spintronics]].

Therapeutic products based on responsive [[nanomaterials]], such as the highly deformable, stress-sensitive [[Transfersome]] vesicles, are approved for human use in some countries.<ref>{{cite journal | vauthors = Rajan R, Jose S, Mukund VP, Vasudevan DT | title = Transferosomes - A vesicular transdermal delivery system for enhanced drug permeation | journal = Journal of Advanced Pharmaceutical Technology & Research | volume = 2 | issue = 3 | pages = 138–143 | date = July 2011 | pmid = 22171309 | pmc = 3217704 | doi = 10.4103/2231-4040.85524 | doi-access = free }}</ref>

==Applications==

[[File:Threshold formation nowatermark.gif|thumb|right|upright=1.8|One of the major applications of nanotechnology is in the area of [[nanoelectronics]] with [[MOSFET]]'s being made of small [[nanowire]]s ≈10 nm in length. Here is a simulation of such a nanowire.]]

[[File:A-simple-and-fast-fabrication-of-a-both-self-cleanable-and-deep-UV-antireflective-quartz-1556-276X-7-430-S1.ogv|thumb|Nanostructures provide this surface with [[superhydrophobicity]], which lets [[water droplet]]s roll down the [[inclined plane]].]]

[[File:Nanowire laser.png|thumb|Nanowire lasers for ultrafast transmission of information in light pulses]]{{Update section|date=May 2024}}{{Main|List of nanotechnology applications}}

As of August 21, 2008, the [[Project on Emerging Nanotechnologies]] estimated that over 800 manufacturer-identified nanotech products were publicly available, with new ones hitting the market at a pace of 3–4 per week.<ref name="emergingnano"/> Most applications are "first generation" passive nanomaterials that includes titanium dioxide in sunscreen, cosmetics, surface coatings,<ref>{{cite journal| vauthors = Kurtoglu ME, Longenbach T, Reddington P, Gogotsi Y |year=2011|title=Effect of Calcination Temperature and Environment on Photocatalytic and Mechanical Properties of Ultrathin Sol–Gel Titanium Dioxide Films|journal=Journal of the American Ceramic Society|volume=94|issue=4|pages=1101–8|doi=10.1111/j.1551-2916.2010.04218.x}}</ref> and some food products; Carbon allotropes used to produce [[gecko tape]]; silver in [[food packaging]], clothing, disinfectants, and household appliances; zinc oxide in sunscreens and cosmetics, surface coatings, paints and outdoor furniture varnishes; and cerium oxide as a fuel catalyst.<ref name="americanelements"/>

In the electric car industry, single wall carbon nanotubes (SWCNTs) address key [[lithium-ion battery]] challenges, including energy density, charge rate, service life, and cost. SWCNTs connect electrode particles during charge/discharge process, preventing battery premature degradation. Their exceptional ability to wrap active material particles enhanced electrical conductivity and physical properties, setting them apart multi-walled carbon nanotubes and carbon black.<ref>{{cite journal | vauthors = Guo M, Cao Z, Liu Y, Ni Y, Chen X, Terrones M, Wang Y | title = Preparation of Tough, Binder-Free, and Self-Supporting LiFePO₄ Cathode by Using Mono-Dispersed Ultra-Long Single-Walled Carbon Nanotubes for High-Rate Performance Li-Ion Battery | journal = Advanced Science | volume = 10 | issue = 13 | pages = e2207355 | date = May 2023 | pmid = 36905241 | pmc = 10161069 | doi = 10.1002/advs.202207355 }}</ref><ref>{{Cite journal | vauthors = Jimenez NP, Balogh MP, Halalay IC |date= April 2021 |title=High Porosity Single-Phase Silicon Negative Electrode Made with Phase-Inversion |journal=Journal of the Electrochemical Society |volume=168 |issue=4 |pages=040507 |doi=10.1149/1945-7111/abe3f1 |issn=0013-4651|doi-access=free |bibcode= 2021JElS..168d0507J }}</ref><ref>{{Cite web |title=Single wall CNT cells: high energy density anodes & cathodes | publisher = OCSiAl |url=https://tuball.com/nanotubes-in/li-ion-batteries |access-date=2024-07-02 | work = tuball.com |language=en}}</ref>

Further applications allow [[tennis ball]]s to last longer, [[golf ball]]s to fly straighter, and [[bowling ball]]s to become more durable. [[Trouser]]s and [[socks]] have been infused with nanotechnology to last longer and lower temperature in the summer. [[Bandage]]s are infused with silver nanoparticles to heal cuts faster.<ref name="nnin">{{cite web|url=http://www.nnin.org/nnin_nanoproducts.html|title=Nanotechnology Consumer Products|work=National Nanotechnology Infrastructure Network |year=2010|access-date=November 23, 2011|url-status=live|archive-url=https://web.archive.org/web/20120119092143/http://www.nnin.org/nnin_nanoproducts.html|archive-date=January 19, 2012 }}</ref> [[Video game console]]s and [[personal computer]]s may become cheaper, faster, and contain more memory thanks to nanotechnology.<ref>{{cite web|url=http://www.nanoandme.org/nano-products/computing-and-electronics|title=Nano in computing and electronics|archive-url=https://web.archive.org/web/20111114034926/http://www.nanoandme.org/nano-products/computing-and-electronics/|archive-date=2011-11-14|website=NanoandMe.org}}</ref> Also, to build structures for on chip computing with light, for example on chip optical quantum information processing, and picosecond transmission of information.<ref>{{cite journal | vauthors = Mayer B, Janker L, Loitsch B, Treu J, Kostenbader T, Lichtmannecker S, Reichert T, Morkötter S, Kaniber M, Abstreiter G, Gies C, Koblmüller G, Finley JJ | title = Monolithically Integrated High-β Nanowire Lasers on Silicon | journal = Nano Letters | volume = 16 | issue = 1 | pages = 152–156 | date = January 2016 | pmid = 26618638 | doi = 10.1021/acs.nanolett.5b03404 | bibcode = 2016NanoL..16..152M }}</ref>

Nanotechnology may have the ability to make existing medical applications cheaper and easier to use in places like the doctors' offices and at homes.<ref>{{cite web|url=http://www.nanoandme.org/nano-products/medical|title=Nano in medicine|archive-url=https://web.archive.org/web/20111114035018/http://www.nanoandme.org/nano-products/medical/|archive-date=2011-11-14|website=NanoandMe.org}}</ref> Cars use [[nanomaterial]]s in such ways that car parts require fewer [[metal]]s during manufacturing and less [[fuel]] to operate in the future.<ref>{{cite web|url=http://www.nanoandme.org/nano-products/transport/|title=Nano in transport|archive-url=https://web.archive.org/web/20111029130940/http://www.nanoandme.org/nano-products/transport/|archive-date=2011-10-29|website=NanoandMe.org}}</ref>

Nanoencapsulation involves the enclosure of active substances within carriers. Typically, these carriers offer advantages, such as enhanced bioavailability, controlled release, targeted delivery, and protection of the encapsulated substances. In the medical field, nanoencapsulation plays a significant role in [[drug delivery]]. It facilitates more efficient drug administration, reduces side effects, and increases treatment effectiveness. Nanoencapsulation is particularly useful for improving the bioavailability of poorly water-soluble drugs, enabling controlled and sustained drug release, and supporting the development of targeted therapies. These features collectively contribute to advancements in medical treatments and patient care.<ref>{{cite journal | vauthors = Kumari A, Singla R, Guliani A, Yadav SK | title = Nanoencapsulation for drug delivery | journal = EXCLI Journal | volume = 13 | pages = 265–286 | date = March 2014 | pmid = 26417260 | pmc = 4464443 }}</ref><ref>{{Cite web | vauthors = Suganya V, Anuradha V |date=March 2017 |title=Microencapsulation and Nanoencapsulation: A Review |url=https://www.researchgate.net/publication/318501373 |access-date=28 October 2023 |website=ResearchGate}}</ref>

Nanotechnology may play role in [[Tissue Engineering|tissue engineering]]. When designing scaffolds, researchers attempt to mimic the nanoscale features of a [[Cell (biology)|cell]]'s microenvironment to direct its differentiation down a suitable lineage.<ref>{{cite journal | vauthors = Cassidy JW | title = Nanotechnology in the Regeneration of Complex Tissues | journal = Bone and Tissue Regeneration Insights | volume = 5 | pages = 25–35 | date = November 2014 | pmid = 26097381 | pmc = 4471123 | doi = 10.4137/BTRI.S12331 }}</ref> For example, when creating scaffolds to support bone growth, researchers may mimic [[osteoclast]] resorption pits.<ref>{{cite journal | vauthors = Cassidy JW, Roberts JN, Smith CA, Robertson M, White K, Biggs MJ, Oreffo RO, Dalby MJ | title = Osteogenic lineage restriction by osteoprogenitors cultured on nanometric grooved surfaces: the role of focal adhesion maturation | journal = Acta Biomaterialia | volume = 10 | issue = 2 | pages = 651–660 | date = February 2014 | pmid = 24252447 | pmc = 3907683 | doi = 10.1016/j.actbio.2013.11.008 | url = http://eprints.soton.ac.uk/367171/ | url-status = live | archive-url = https://web.archive.org/web/20170830234634/https://eprints.soton.ac.uk/367171/ | author-link8 = Matthew Dalby | archive-date = 2017-08-30 }}</ref>

Researchers used [[DNA origami]]-based nanobots capable of carrying out logic functions to target drug delivery in cockroaches.<ref>{{cite journal | vauthors = Amir Y, Ben-Ishay E, Levner D, Ittah S, Abu-Horowitz A, Bachelet I | title = Universal computing by DNA origami robots in a living animal | journal = Nature Nanotechnology | volume = 9 | issue = 5 | pages = 353–357 | date = May 2014 | pmid = 24705510 | pmc = 4012984 | doi = 10.1038/nnano.2014.58 | bibcode = 2014NatNa...9..353A }}</ref>

A nano bible (a .5mm2 silicon chip) was created by the [[Technion – Israel Institute of Technology|Technion]] in order to increase youth interest in nanotechnology.<ref>{{Cite web |date=2015-11-04 |title=Technion Nano Bible, world's smallest, displayed at Smithsonian |url=https://www.jpost.com/business-and-innovation/tech/technion-nano-bible-worlds-smallest-displayed-at-smithsonian-432038 |access-date=2024-06-25 |website=The Jerusalem Post {{!}} JPost.com |language=en}}</ref>

==Implications==

{{Main|Implications of nanotechnology}}

One concern is the effect that industrial-scale manufacturing and use of nanomaterials will have on human health and the environment, as suggested by [[nanotoxicology]] research. For these reasons, some groups advocate that nanotechnology be regulated. However, regulation might stifle scientific research and the development of beneficial innovations. [[Public health]] research agencies, such as the [[National Institute for Occupational Safety and Health]] research potential health effects stemming from exposures to nanoparticles.<ref name="niosh">{{cite web|url=https://www.cdc.gov/niosh/topics/nanotech/?s_cid=3ni7d2ms082915|title=Nanotechnology |work=NIOSH Workplace Safety and Health Topic|publisher=National Institute for Occupational Safety and Health|date=June 15, 2012|access-date=2012-08-24|url-status=live|archive-url=https://web.archive.org/web/20150904005250/http://www.cdc.gov/niosh/topics/nanotech/?s_cid=3ni7d2ms082915|archive-date=September 4, 2015}}</ref><ref name="nioshnano">{{Cite journal|url=https://www.cdc.gov/niosh/docs/2013-101/|journal=NIOSH Publications and Products |title=Filling the Knowledge Gaps for Safe Nanotechnology in the Workplace|publisher=National Institute for Occupational Safety and Health|date=November 7, 2012|access-date=2012-11-08|url-status=live|archive-url=https://web.archive.org/web/20121111211819/http://www.cdc.gov/niosh/docs/2013-101/|archive-date=November 11, 2012|doi=10.26616/NIOSHPUB2013101|doi-access=free |id=2013-101}}</ref>

Nanoparticle products may have [[unintended consequences]]. Researchers have discovered that [[bacteriostatic]] silver nanoparticles used in socks to reduce foot odor are released in the wash.<ref>{{cite journal | vauthors = Lubick N | title = Silver socks have cloudy lining | journal = Environmental Science & Technology | volume = 42 | issue = 11 | pages = 3910 | date = June 2008 | pmid = 18589943 | doi = 10.1021/es0871199 | s2cid = 26887347 | bibcode = 2008EnST...42.3910L }}</ref> These particles are then flushed into the wastewater stream and may destroy bacteria that are critical components of natural ecosystems, farms, and waste treatment processes.<ref>{{cite book | vauthors = Murray RG | chapter = A Perspective on S-Layer Research | date = 1993 | veditors = Beveridge TJ, Koval SF | title = Advances in Bacterial Paracrystalline Surface Layers | publisher = Plenum Press | isbn = 978-0-306-44582-8 | doi = 10.1007/978-1-4757-9032-0_1 | pages = 3–9 }}</ref>

Public deliberations on [[risk perception]] in the US and UK carried out by the Center for Nanotechnology in Society found that participants were more positive about nanotechnologies for energy applications than for health applications, with health applications raising moral and ethical dilemmas such as cost and availability.<ref name="harthorn">{{cite web| vauthors = Harthorn BH |date=2009-01-23|url=http://nanotechnologytoday.blogspot.com/2009/01/people-in-us-and-uk-show-strong.html|title=People in the US and the UK show strong similarities in their attitudes toward nanotechnologies|archive-url=https://web.archive.org/web/20110823001736/http://nanotechnologytoday.blogspot.com/2009/01/people-in-us-and-uk-show-strong.html|archive-date=2011-08-23|website=Nanotechnology Today}}</ref>

Experts, including director of the Woodrow Wilson Center's Project on Emerging Nanotechnologies David Rejeski, testified<ref>{{cite web|url=http://www.nanotechproject.org/news/archive/successful_commercialization_depends_on/|title=Testimony of David Rejeski for U.S. Senate Committee on Commerce, Science and Transportation|archive-url=https://web.archive.org/web/20080408064825/http://www.nanotechproject.org/news/archive/successful_commercialization_depends_on/|archive-date=2008-04-08|work=Project on Emerging Nanotechnologies|access-date=2008-03-07}}</ref> that commercialization depends on adequate oversight, risk research strategy, and public engagement. As of 206 [[Berkeley, California]] was the only US city to regulate nanotechnology.<ref>{{cite news| vauthors = DelVecchio R |date=2006-11-24|url=http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2006/11/24/MNGP9MJ4KI1.DTL|title=Berkeley considering need for nano safety|archive-url=https://web.archive.org/web/20100902211655/http://articles.sfgate.com/2006-11-24/news/17319373_1_hazardous-materials-nanoparticles-uc-berkeley|archive-date=2010-09-02|website=SFGate }}</ref>

===Health and environmental concerns===

[[File:NIOSH Nano Research - Engineering Controls for Nanomaterial Production and Handling Processes.webm|thumb|A video on the health and safety implications of nanotechnology]]

{{Main|Health and safety hazards of nanomaterials|Pollution from nanomaterials}}

Inhaling airborne nanoparticles and nanofibers may contribute to [[pulmonary disease]]s, e.g. [[fibrosis]].<ref>{{cite journal | vauthors = Byrne JD, Baugh JA | title = The significance of nanoparticles in particle-induced pulmonary fibrosis | journal = McGill Journal of Medicine | volume = 11 | issue = 1 | pages = 43–50 | date = January 2008 | pmid = 18523535 | pmc = 2322933 }}</ref> Researchers found that when rats breathed in nanoparticles, the particles settled in the brain and lungs, which led to significant increases in biomarkers for inflammation and stress response<ref>{{cite web| vauthors = Elder A |date=2006-08-03|url=http://www.urmc.rochester.edu/pr/news/story.cfm?id=1191|title=Tiny Inhaled Particles Take Easy Route from Nose to Brain|website=University of Rochester Medical Center|archive-url=https://web.archive.org/web/20150123193204/http://www.urmc.rochester.edu/news/story/index.cfm?id=1191|archive-date=2015-01-23}}</ref> and that nanoparticles induce skin aging through oxidative stress in hairless mice.<ref>{{cite journal | vauthors = Wu J, Liu W, Xue C, Zhou S, Lan F, Bi L, Xu H, Yang X, Zeng FD | title = Toxicity and penetration of TiO2 nanoparticles in hairless mice and porcine skin after subchronic dermal exposure | journal = Toxicology Letters | volume = 191 | issue = 1 | pages = 1–8 | date = December 2009 | pmid = 19501137 | doi = 10.1016/j.toxlet.2009.05.020 }}</ref><ref>{{cite journal | vauthors = Jonaitis TS, Card JW, Magnuson B | title = Concerns regarding nano-sized titanium dioxide dermal penetration and toxicity study | journal = Toxicology Letters | volume = 192 | issue = 2 | pages = 268–269 | date = February 2010 | pmid = 19836437 | doi = 10.1016/j.toxlet.2009.10.007 }}</ref>

A two-year study at [[UCLA Fielding School of Public Health|UCLA's School of Public Health]] found lab mice consuming nano-titanium dioxide showed DNA and chromosome damage to a degree "linked to all the big killers of man, namely cancer, heart disease, neurological disease and aging".<ref>{{cite web| vauthors = Schneider A |date=2010-03-24|url=http://www.aolnews.com/nanotech/article/amid-nanotechs-dazzling-promise-health-risks-grow/19401235|title=Amid Nanotech's Dazzling Promise, Health Risks Grow|archive-url=https://web.archive.org/web/20100326130438/http://www.aolnews.com/nanotech/article/amid-nanotechs-dazzling-promise-health-risks-grow/19401235|archive-date=2010-03-26|website=AOL News}}</ref>

A ''[[Nature Nanotechnology]]'' study suggested that some forms of [[carbon nanotube]]s could be as harmful as [[asbestos]] if inhaled in sufficient quantities. [[Anthony Seaton]] of the [[Institute of Occupational Medicine]] in Edinburgh, Scotland, who contributed to the article on [[carbon nanotube]]s said "We know that some of them probably have the potential to cause [[mesothelioma]]. So those sorts of materials need to be handled very carefully."<ref>{{cite news| vauthors = Weiss R |date=2008|url=https://www.washingtonpost.com/wp-dyn/content/article/2008/05/20/AR2008052001331.html?hpid=sec-health&sid=ST2008052100104|title=Effects of Nanotubes May Lead to Cancer, Study Says|newspaper=[[The Washington Post]] |archive-url=https://web.archive.org/web/20110629001411/http://www.washingtonpost.com/wp-dyn/content/article/2008/05/20/AR2008052001331.html?hpid=sec-health&sid=ST2008052100104|archive-date=2011-06-29}}</ref> In the absence of specific regulation forthcoming from governments, Paull and Lyons (2008) have called for an exclusion of engineered nanoparticles in food.<ref>{{cite journal| vauthors = Paull J, Lyons K |year=2008 |url=http://orgprints.org/13569/1/13569.pdf|title=Nanotechnology: The Next Challenge for Organics|journal=Journal of Organic Systems|volume=3|pages=3–22|url-status=live|archive-url=https://web.archive.org/web/20110718172822/http://orgprints.org/13569/1/13569.pdf|archive-date=2011-07-18}}</ref> A newspaper article reports that workers in a paint factory developed serious lung disease and nanoparticles were found in their lungs.<ref>{{cite news|title=Nanoparticles used in paint could kill, research suggests|newspaper=Telegraph|url=https://www.telegraph.co.uk/health/healthnews/6016639/Nanoparticles-used-in-paint-could-kill-research-suggests.html|___location=London| vauthors = Smith R |date=August 19, 2009|access-date=May 19, 2010|url-status=dead|archive-url=https://web.archive.org/web/20100315162044/http://www.telegraph.co.uk/health/healthnews/6016639/Nanoparticles-used-in-paint-could-kill-research-suggests.html|archive-date=March 15, 2010 }}</ref><ref>{{cite news|url=https://www.bbc.com/news/health-19355196|title=Nanofibres 'may pose health risk'|archive-url=https://web.archive.org/web/20120825143122/http://www.bbc.co.uk/news/health-19355196|archive-date=2012-08-25|website=BBC News|date=2012-08-24}}</ref><ref>{{cite journal | vauthors = Schinwald A, Murphy FA, Prina-Mello A, Poland CA, Byrne F, Movia D, Glass JR, Dickerson JC, Schultz DA, Jeffree CE, Macnee W, Donaldson K | title = The threshold length for fiber-induced acute pleural inflammation: shedding light on the early events in asbestos-induced mesothelioma | journal = Toxicological Sciences | volume = 128 | issue = 2 | pages = 461–470 | date = August 2012 | pmid = 22584686 | doi = 10.1093/toxsci/kfs171 | doi-access = free }}</ref><ref>{{cite web | vauthors = Stix G | date = July 2007 |url=https://www.scientificamerican.com/article/chronic-inflammation-cancer/ |title=Is Chronic Inflammation the Key to Unlocking the Mysteries of Cancer?| work = [[Scientific American]]}}</ref>

==Regulation==

{{Main|Regulation of nanotechnology}}

Calls for tighter regulation of nanotechnology have accompanied a debate related to human health and safety risks.<ref>{{cite journal |url= http://www.nanolabweb.com/index.cfm/action/main.default.viewArticle/articleID/290/CFID/3564274/CFTOKEN/43473772/index.html| title= Nanobiotechnology Regulation: A Proposal for Self-Regulation with Limited Oversight| vauthors = Rollins K | publisher = Nems Mems Works, LLC | journal = Nanotechnology Law Business | volume = 6 | issue = 2 |access-date=2 September 2010|url-status=live|archive-url=https://web.archive.org/web/20110714153112/http://www.nanolabweb.com/index.cfm/action/main.default.viewArticle/articleID/290/CFID/3564274/CFTOKEN/43473772/index.html|archive-date=14 July 2011}}</ref> Some regulatory agencies cover some nanotechnology products and processes – by "bolting on" nanotechnology to existing regulations – leaving clear gaps.<ref>{{cite journal|vauthors=Bowman D, Hodge G|title=Nanotechnology: Mapping the Wild Regulatory Frontier|journal=Futures|volume=38|pages=1060–73|year=2006|doi=10.1016/j.futures.2006.02.017|issue=9}}</ref> Davies proposed a road map describing steps to deal with these shortcomings.<ref>{{cite web| vauthors = Davies JC |date=2008|url=http://www.nanotechproject.org/publications/archive/pen13/|title=Nanotechnology Oversight: An Agenda for the Next Administration|archive-url=https://web.archive.org/web/20081120154647/http://www.nanotechproject.org/publications/archive/pen13/|archive-date=2008-11-20}}.</ref>

Andrew Maynard, chief science advisor to the Woodrow Wilson Center's Project on Emerging Nanotechnologies, reported insufficient funding for human health and safety research, and as a result inadequate understanding of human health and safety risks.<ref>{{cite web| vauthors = Maynard A |url=http://www.science.house.gov/publications/Testimony.aspx?TID=12957|title=Testimony by Dr. Andrew Maynard for the U.S. House Committee on Science and Technology|date=2008-04-16|access-date=2008-11-24|archive-url=https://web.archive.org/web/20101205122135/http://science.house.gov/publications/Testimony.aspx?TID=12957|archive-date=2010-12-05}}</ref> Some academics called for stricter application of the [[precautionary principle]], slowing marketing approval, enhanced labelling and additional safety data.<ref>{{Cite journal|doi=10.1007/s11569-008-0041-z|title=Sunscreen Safety: The Precautionary Principle, the Australian Therapeutic Goods Administration and Nanoparticles in Sunscreens|journal=NanoEthics|volume=2|issue=3|pages=231–240 |year=2008 | vauthors = Faunce T, Murray K, Nasu H, Bowman D |s2cid=55719697 }}</ref>

A Royal Society report identified a risk of nanoparticles or nanotubes being released during disposal, destruction and recycling, and recommended that "manufacturers of products that fall under [[extended producer responsibility]] regimes such as end-of-life regulations publish procedures outlining how these materials will be managed to minimize possible human and environmental exposure".<ref name="royalsociety" />

==See also==

{{Portal|Science|Technology}}

{{Main|Outline of nanotechnology}}

{{div col|colwidth=20em}}

* [[Carbon nanotube]]

* [[Electrostatic deflection (molecular physics/nanotechnology)]]

* [[Energy applications of nanotechnology]]

* [[Ethics of nanotechnologies]]

* [[Ion implantation-induced nanoparticle formation]]

* [[Gold nanoparticle]]

* [[List of emerging technologies]]

* [[List of nanotechnology organizations]]

* [[List of software for nanostructures modeling]]

* [[Magnetic nanochains]]

* [[Materiomics]]

* [[Nano-thermite]]

* [[Molecular design software]]

* [[Molecular mechanics]]

* [[Nanobiotechnology]]

* [[Nanoelectromechanical relay]]

* [[Nanoengineering]]

* [[Nanofluidics]]

* [[NanoHUB]]

* [[Nanometrology]]

* [[Nanoneuronics]]

* [[Nanoparticle]]

* [[Nanoscale networks]]

* [[Nanotechnology education]]

* [[Nanotechnology in fiction]]

* [[Nanotechnology in water treatment]]

* [[Nanoweapons]]

* [[National Nanotechnology Initiative]]

* [[Self-assembly of nanoparticles]]

* [[Top-down and bottom-up#Nanotechnology|Top-down and bottom-up]]

* [[Translational research]]

* [[Wet nanotechnology]]

{{div col end}}

==References==

{{reflist|30em}}

==External links==

{{Commons}}

{{Wikiquote}}

{{Wiktionary}}

{{Wikiversity department}}

* [http://www.vega.org.uk/video/programme/3 What is Nanotechnology?] (A Vega/BBC/OU Video Discussion).

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