nanotechnology

from Wikipedia, the free encyclopedia
New materials such as fullerenes (df) or carbon nanotubes (h) are nanotechnology and are already being used in many areas
The size of the transistors (see picture) of a commercially available microprocessor is already in the range of nanotechnology. Structures 5 nm wide are achieved.

The collective term nanotechnology , often also nanotechnology ( ancient Greek νᾶνος nános 'dwarf'), is based on the same order of magnitude of the nanoparticles, from the single atom to a structure size of 100 nanometers (nm): a nanometer is a billionth Meters (10 −9  m). This order of magnitude describes a limit area in which the surface properties play an increasingly important role compared to the volume properties of the materials and quantum physical effects must increasingly be taken into account. In nanotechnology, one advances to length scales on which the size in particular determines the properties of an object. One speaks of "size-induced functionalities".

The term is used today to describe the corresponding research in cluster , semiconductor and surface physics , surface and other areas of chemistry as well as in sub-areas of mechanical engineering and food technology ( nano-food ).

Nanomaterials already play an important role today. They are mostly produced chemically or using mechanical methods. Some of these are commercially available and used in commercial products, others are important model systems for physico-chemical and materials science research.

Nanoelectronics is also important . Their affiliation with nanotechnology is not seen uniformly in scientific and research policy practice. The effects and influence of the mostly artificially produced particles on the environment are unclear and unexplored in many areas.

A development direction in nanotechnology can be seen as a continuation and expansion of microtechnology ( top-down approach), but further downsizing of micrometer structures usually requires completely unconventional new approaches. In nanotechnology, chemistry often follows the opposite approach: bottom-up . Chemists commonly involved in molecular, i. H. Working on sub-nanometer dimensions, building larger nanoscale molecular assemblies from a large number of individual molecular units. Dendrimers are an example .

A small branch of nanotechnology deals with nanomachines (see molecular machine ) or nanobots .

Origins of Nanotechnology

As the father of nanotechnology is Richard Feynman due to its held in 1959 lecture " There's Plenty of Room at the Bottom " ( At the bottom is a lot of space ), even if only Norio Taniguchi the term "nanotechnology" in 1974 for the first time used:

"Nano-technology mainly consists of the processing of separation, consolidation, and deformation of materials by one atom or one molecule."

Nanotechnology in the sense of this definition is the change of materials, be it atom by atom or molecule by molecule. This includes that the critical properties of materials or devices can be in the nanometer range, and that these materials and devices are constructed from individual atoms or molecules. Today, however, nanotechnology is only rarely used in this narrow sense; today (as explained above) the production of nanomaterials by chemical means is also included in this term.

Independently of Taniguchi, Eric Drexler made the term widely known in 1986 . With his book Engines of Creation, he inspired many of today's well-known scientists and physicians, including Richard E. Smalley ( fullerene ), to study nanotechnology. Drexler's definition of nanotechnology is stricter than the Taniguchi's: It is limited to the construction of complex machines and materials from individual atoms.

According to this definition, today's nanotechnology does not fall under what Drexler sees as nanotechnology. In the course of the 1990s, this prompted Drexler to rename his concept of nanotechnology to delimit it into molecular nanotechnology (MNT), because the term was and is often used to designate all work that deals with nanostructures, even if it involves ordinary chemical , pharmaceuticals or physical methods can be used.

In fact, many scientists are currently skeptical to openly negative about Drexler's vision of nanotechnology. Even if the advocates of the MNT believe that their opponents have not yet succeeded in making convincing scientific arguments against the feasibility of MNT, many consider the feasibility to be unlikely; even though Drexler and Nanosystems published a textbook on MNT in 1991, which, based on his doctoral thesis at the Massachusetts Institute of Technology (MIT), describes in scientific form the steps necessary to implement it. Over the years, some of Drexler's assumptions have been experimentally confirmed, but there remain many reservations that stand in the way of their realization: Even if it were possible to make a metal nanomotor , for example , it would not be functional for long: even the film of water that is formed due to the condensation of air humidity on the metal surface would paralyze the engine. Metals such as iron, steel or aluminum form a thin oxide film in air that does not interfere with normal workpieces. The oxidation of nanometals usually leads to complete conversion into the oxide. A nanomotor made of metal would be burned by the oxygen in the air. So one could only build an engine made of a substance that does not oxidize when exposed to water. If you wanted to move macromolecules past each other in a vacuum or in air at a distance of less than a few atomic diameters , then they would stick to each other due to the Van der Waals forces . But if the macromolecules in water or in another suitable liquid embedding, then the fluid takes over the Van der Waals force, and can be the macromolecules friction past each move. This is how living cells work , and the scourge drive of the bacteria reaches 50 revolutions per second. Holding or letting go of individual atoms or molecules purely mechanically is also made more difficult by the Van der Waals forces, which has been referred to as the "sticky finger problem". This problem, as well as the purely mechanical creation of covalent bonds , was overcome by applying an electrical voltage , which was shown here.

Nanotechnology as a trend word

Nanotechnology in the Drexler sense draws its fascination from its ambivalent nature. Its proponents claim that the fully developed MNT enables material wealth for the whole of humanity, the settlement of space and individual quasi-immortality; on the other hand, it offers the possibility of catastrophe for the whole of humanity through wars, global terrorist attacks, an insurmountable police state and total alienation of today's image of man through genetic engineering . These very contradicting aspects make nanotechnology in Drexler's sense particularly interesting for literature. Numerous science fiction authors have included nanotechnology as an element in their stories and implemented it as a book or film. The negative aspects of the technology are often highlighted and processed. An example of living beings in film and television that use nanotechnology, among other things, are the Borg .

Most scientists consider Drexler's visions to be exaggerated. Despite his studies, some consider him more or less a good science fiction writer.

Nanotechnology has also been described as a political project. The vagueness of the term would therefore make the attraction of nanotechnology in the first place.

Role models in nature

Lotus effect

Effects such as those used by many nanotechnologies often occur in nature. For example, there are nanometer-sized hairs on fly legs, which are the reason why these insects can run on ceilings and walls . The best-known example of nanotechnology is the lotus effect : Fine nanostructures ensure that water pearls off the leaf of the lotus flower and the adhesion of dirt particles is minimized. In the lime of mussel shells, organic and inorganic substances in the nano range are so closely lined up that mussel shells are extremely stable and resistant, the same effect also exists in human bones . Furthermore, a large number of nanoparticles are released in every combustion . The enzyme - molecules that ribosomes , and the above-mentioned scourge drives the bacteria are natural nanomachines.

Today's nanotechnological products

Many nanotechnology products have already been on the market, some for more than 40 years, but in the wake of the general media hype (“nano hype”) they are often given the prefix nano in retrospect. Everyday uses include:

  • numerous pigments and other additives ( additives ) for paints and plastics, such as for example highly dispersed silicic acids or carbon black . Such paints can be used, among other things, as a protective coating for car bodies .
  • Nano-coating that can clean themselves with the help of the lotus effect . A nanoscale binder acts as an alternative to chromate layers in automotive painting .
  • Sun creams that use nanoscale titanium dioxide to protect against ultraviolet radiation.
  • Nanosilicates that are attached to the inside of bottles, for example to allow ketchup to flow out better.
  • Nano-coatings that make plastic bottles gas-tight.
  • Garments that have a nano-composite and thus have a dirt-repellent effect. This property is based on the fact that the dirt particles do not adhere to the tiny nano-elements.

Typical modern representatives of nanotech products are the so-called quantum dots (English quantum dots ). Even modern processors have structures that are smaller than 100 nm and can therefore be described as nanotechnological, although this is not common as they are manufactured using conventional photolithographic processes . Nowadays, special areas of application for nanotechnology are the coating of surfaces or the manufacture of dental filling materials. In these applications, nanofillers no longer behave like an amorphous substance, but take on the properties of liquids.

It has been proven that nano-effects were used in the manufacture of a Lykurgos beaker in the 4th century AD.

Interplay of the sciences

A great specialty of nanotechnology is that it represents an interdisciplinary interaction of many, actually specialized, fields of the natural sciences . Physics plays an important role, if only in the construction of the microscope for investigation and above all because of the laws of quantum mechanics . Chemistry is used for a desired structure of matter and atomic arrangements . The targeted use of nanoparticles in medicine should help with certain diseases. On the other hand, structures such as B. two-dimensional crystals, constructed on a nanometer scale as DNA origami or DNA machine , because these can be easily manipulated with previous technologies (e.g. the polymerase chain reaction and phosphoramidite synthesis ). Science has reached a point here where the boundaries between the various disciplines are blurring, which is why nanotechnology is also called a convergent technology.

Potential uses

The currently foreseeable goal of nanotechnology is the further miniaturization of microelectronics and optoelectronics as well as the industrial production of novel materials such as B. Nanotubes . For the production of such structures, new or further developed techniques are required, which are often referred to with the prefix “nano-”. For example, new structuring techniques in semiconductor technology (cf. photolithography ), which enable the production of structures on the nanometer scale, are also known as nanolithography .

In medicine, nanoparticles offer the opportunity to develop new types of diagnostics and therapeutics , for example contrast media for the imaging methods of computed tomography or magnetic resonance tomography , as well as new drugs with nanoparticles as active substance transporters or depots, for example in cancer therapy. Here, for example, iron oxide-containing nanoparticles are injected into the bloodstream, whereby they are distributed with the bloodstream in the body. Once the tumor has accumulated, it can be heated by an applied magnetic field and thus destroyed. The focus of the research is on the methods by which a targeted accumulation of the nanoparticles in the tumor can be achieved. Surfaces made from nanostructures offer the possibility of developing more durable, biocompatible implants . This discipline of nanotechnology is also known as nanobiotechnology or nanomedicine .

In the agriculture of nanotechnology also possible applications. In Germany, on behalf of the BMELV , research is currently being carried out into the development of nanofibers as a carrier material for pheromones for the benefit of biological plant protection .

The goal of the development in nanotechnology is the digital, programmable manipulation of matter at the atomic level and the resulting molecular production or molecular nanotechnology (MNT). Investigations down to the atomic level are now possible with the electron microscope , the scanning tunneling microscope or the atomic force microscope . However, they can also be used to actively shape individual nanostructures.

criticism

At the end of the 1990s , nanotechnology gained more public and media interest. With growing promises (“third industrial revolution ”), voices criticizing nanotechnology also came to the public. An initial function for the discussion in Germany can be ascribed to an article by Bill Joy, " Why the future doesn't need us ", originally published in April 2000 in Wired magazine . With a dramatic gesture, Joy points to the serious consequences of the new technologies - genetic engineering, nanotechnology, robotics - and calls for it to be renounced: In view of the uncertainty and limited knowledge about the progress of technical developments and the far-reaching potential of nanotechnology, risks arise that can only be avoided by doing without Development and use of these techniques could evade. As a result, a whole series of studies and position papers are published by scientific institutions and non-governmental organizations, which deal with the possible consequences of nanotechnology from different perspectives and differ widely in their (political) recommendations.

In July 2004 the Royal Society and the Royal Academy of Engineering presented a comprehensive report calling for stronger regulation of nanotechnologies. The report had been commissioned by the British government a year earlier. According to studies by the Center for Biological and Environmental Nanotechnology (CBEN) at Rice University , nanoparticles accumulate in living things through the food chain. This does not necessarily mean harmful, the authors emphasize, but point to other technologies that were also considered harmless at the beginning. Risk researcher and director of the Stockholm Environment Institute, Roger Kasperson, sees parallels in the nanotechnology debate with the early atomic age .

In 2003 the ETC Group called for a moratorium on nanotechnology because of feared incalculable risks. In the same year Greenpeace published a critical study on nanotechnology. The criticism of a possible unpredictability of the new technology also became popular through fictional texts such as the 2002 novel Prey by Michael Crichton .

Militant actions

In May and August 2011, several nanotechnology scientists at the Instituto Politécnico Nacional and Instituto Tecnológico y de Estudios Superiores de Monterrey were targeted in attacks that left injured. The Individuals Tending To Savagery (ITS) group committed to the attacks. In a manifesto published on August 23, the fear is expressed that nanoparticles could reproduce in an uncontrolled manner and wipe out life on earth. Theodore Kaczynski is praised in it.

Risks and Dangers

In 2004 the report Nanotechnology appeared. Small parts - big future? the Swiss reinsurance company Swiss Re . The report of one of the world's largest reinsurers expresses the fear that nanotubes could have similar effects on human health as asbestos . It is recommended that insurance companies never insure the risks of nanotechnology indefinitely. In order to avoid cumulative consequential damage for the industry, there is a requirement that insurance contracts for nanotechnology should always include a maximum amount of damage to be covered.

In June 2005 Allianz Versicherungs-AG published a study together with the OECD on the opportunities and risks of nanotechnology. The bottom line: Research and industry should develop well-founded knowledge about risks. International standards, long-term observation and risk transfer are important. "The real risk of nanotechnology," according to the study, "is the gap that exists between its dynamic development and the knowledge of possible dangers and the valid safety standards to avoid negative effects." The Allianz experts involved warn of "possible [n] Risks [...] that could not only have health consequences, but also far-reaching economic consequences if they are not dealt with professionally. "

On April 8, 2006, the Washington Post published an article titled "Nanotech Raises Worker-Safety Questions," complaining that "No state or federal occupational health and safety rules address the specific hazards of nanomaterials, although many laboratory and animal studies have shown." have that nanoparticles [...] cause strange biological reactions and can be much more toxic than larger particles of the same chemicals ”. The article tells of government advisors who do not even know what exactly to focus their research on, on the basis of which the necessary health and safety measures will ultimately be developed. Meanwhile, the handling of nanomaterials in the industry continues unchecked and without safety standards.

At the annual meeting of the American Association for Cancer Research in April 2007, a study by researchers from the University of Massachusetts was presented, which found that nanoparticles in tissue cells can damage DNA and cause cancer. The researchers recommend great caution in manufacturing processes using nanotechnology and avoiding uncontrolled escape into the environment. They complain about the lack of legal and occupational health and safety measures with regard to the handling of nanoparticles: "It would be sensible to limit their release into the environment," said a researcher from the university.

Protective measures against nanoparticles in the workplace

The studies to date show that technical measures that are fundamentally effective against dusts are also suitable for removing nanoparticles and ultra-fine particles . Particles that are smaller than 300 nm are mainly captured by means of deposition through diffusion ( Brownian motion ) and electrostatic forces.

For nanomaterials, too, the physico-chemical properties must be taken into account in the risk assessment and, if necessary, special protective measures must be taken. Nanomaterials can e.g. B. have changed explosion properties or have increased conductivity and affect electrical equipment. Additional protective measures are required for activities with dusty nanomaterials. If technical protective measures are insufficient, personal respiratory protection (e.g. respiratory protection of filter class P3 or P2) must be worn. Additional chemical protection may be necessary under certain circumstances.

public perception

In general, nanotechnology is becoming more and more popular. In 2004 nanotechnology was known to 15% of people in Germany , in 2007 it was already 52%. Overall, people rate nanotechnology positively: 66% think that the opportunities outweigh the risks. Consumers see good opportunities for nanotechnology, especially in the medical sector . In contrast, in food , only 31% are in favor of nanotechnology.

NanoDialog and NanoKommission

In 2006, a so-called NanoKommission was set up at the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety as an advisory body on possible opportunities and risks of nanotechnology for the environment and health. Under the leadership of the former State Secretary Wolf-Michael Catenhusen , representatives from science, business, federal ministries and environmental and consumer protection associations have final recommendations in several expert groups following consultations with over 100 additional external experts as part of the so-called nano-dialogue launched by the former Federal Environment Minister Sigmar Gabriel compiled for the federal government, published on February 2, 2011.

nanoTruck

On the occasion of the “Year of Technology”, the Federal Ministry of Education and Research (BMBF) launched the “ nanoTruck ” initiative in 2004 with the aim of promoting an open, transparent and understandable dialogue with the population about the opportunities, risks and development potential of nanotechnology. The initiative was extended three times as part of newly revised campaigns. The last tour began in April 2011 under the title “Meeting Point Nanoworlds” and ended on schedule in March 2015.

In terms of content, the initiative dealt in particular with application-oriented research and development in the field of nanotechnology in relation to the living and working worlds of modern societies. In addition to information on the fundamentals of nanotechnology, the exhibition included numerous exhibits on various everyday topics, with a separate subject area also being dedicated to accompanying risk research. In addition, workshops and lectures were offered that were primarily aimed at school classes.

See also

Portal: Materials  - Overview of Wikipedia content on the subject of materials

literature

German

Books

Reports

  • Office for Technology Assessment at the German Bundestag (TAB) "Technology Assessment Nanotechnology", BT-Drs. 15/2713 (PDF; 2.5 MB) from March 15, 2004
  • Federal Ministry of Education and Research "nano.DE-Report 2011" - Status quo of nanotechnology in Germany, Bonn / Berlin 2011.
  • Society of German Chemists Nano. Frankfurt / Heidelberg October 2014.

Journal articles

  • J. Kahn: Nanotechnology. Mini robots in action against cancer, extremely small data storage media: How new research is changing our lives. In: National Geographic Germany. June 2006, pp. 132-153.
  • Harald F. Krug: Nanosafety research - are we on the right track? In: Angewandte Chemie . 2014, 126, pp. 12502–12518, doi: 10.1002 / anie.201403367 (Open Access)
  • Nadrian C. Seeman: Career for the Double Helix In: Spectrum of Science. January 2005.
  • Stephan Wagner, Andreas Gondikas, Elisabeth Neubauer, Thilo Hofmann, Frank von der Kammer: Find the difference: synthetic and natural nanoparticles in the environment - release, behavior and fate. In: Angewandte Chemie. 2014, 126, pp. 12604–12626, doi: 10.1002 / anie.201405050 (Open Access)

Other

  • Niels Boeing: The Risks of Nanotechnology. 22nd Chaos Communication Congress, December 29, 2005, ccc.de (PDF); first appeared as: Nanotechnik. In: Technology Review. No. 11, 2005, pp. 32-44
  • Ferdinand Muggenthaler: Nanophysics and Nanoethics. In: Jungle World. December 17, 2003 (Dossier, jungle-world.com )
  • Valentin L. Popov: Contact Mechanics and Friction. A text and application book from nanotribology to numerical simulation. Springer-Verlag, 2009, ISBN 978-3-540-88836-9 , p. 328.

English

  • Joseph Kennedy: Nanotechnology: The Future Is Coming Sooner than You Think . In: Erik Fisher, Cynthia Selin, Jameson M. Wetmore (Eds.): The Yearbook of Nanotechnology in Society . Volume I: Presenting Futures. . Springer Netherlands, 2008, ISBN 978-1-4020-8416-4 , pp. 1–21 , doi : 10.1007 / 978-1-4020-8416-4_1 .
  • The Royal Society (Ed.): Nanoscience and nanotechnologies: opportunities and uncertainties. 2004. nanotec.org.uk

Web links

Commons : Nanotechnology  - collection of images, videos and audio files
Wiktionary: Nanotechnology  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ There's Plenty of Room at the Bottom . in the English Wikipedia
  2. ↑ Richard P. Feynman : A lot of leeway downwards. An invitation to a new field of physics . In: Deutsches Museum (Ed.): Culture & Technology . No. 1 , 2000 ( deutsches-museum.de [PDF; 6.0 MB ; accessed on December 8, 2017] English: There's Plenty of Room at the Bottom . 1960. Translated by Graham Lack, first edition: Engineering and Science, pp. 20 ff., Lecture given on December 29, 1959).
  3. ^ N. Taniguchi: On the basic concept of nanotechnology . In: Proc. Intl. Conf. Prod. Eng. Tokyo, Part II, Japan Society of Precision Engineering . 1974.
  4. ↑ An Application of Mechanochemistry : Charles Day: Creating and Characterizing Individual Molecular Bonds with a Scanning Tunneling Microscope. In: Physics Today On The Web. Retrieved May 14, 2010 .
  5. ^ Joscha Wullweber: Hegemony, Discourse and Political Economy. The nanotechnology project. Nomos, Baden-Baden 2010, ISBN 978-3-8329-5180-1 .
  6. ↑ Nanotechnology in Agriculture. ( Memento from June 12, 2010 in the Internet Archive ) Julius Kühn Institute.
  7. ↑ Abridged German-language reprint of “Why the future doesn't need us” Why the future doesn't need us . In: Frankfurter Allgemeine Zeitung . June 6, 2000.
  8. ↑ "Individuals Tending To Savagery" Anti-Technology Group Sent To Bomb Monterrey Technological Institute professor. ( September 25, 2011 memento on the Internet Archive ) In: Huffington Post. August 10, 2011.
  9. ^ Gerardo Herrera Corral: Stand up against the anti-technology terrorists. In: Nature. 476 (2011), p. 373.
  10. ↑ Nanotechnology. Small parts - big future? ( Memento from July 1, 2014 in the Internet Archive ) Swiss Re, Zurich 2004.
  11. ↑ OECD and Allianz Versicherungs-AG (eds.): Small sizes that matter: Opportunities and Risks of Nanotechnologies. Report in co-operation with the OECD International Futures Program . 2005 ( oecd.org [PDF; accessed March 1, 2013]).
  12. ↑ Allianz Versicherung demands: Take nanotech risks seriously! Allianz Versicherungs-AG, June 3, 2005, accessed September 25, 2006 (press release,).
  13. ↑ Nanotech Raises Worker Safety Questions. washingtonpost.com, April 8, 2006.
  14. ↑ a b Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA): Protective measures for ultra-fine aerosols and nanoparticles in the workplace Retrieved February 21, 2019 .
  15. ↑ bfr.bund.de. Website of the Federal Institute for Risk Assessment . Accessed April 16, 2011.
  16. ↑ press release. BMU, February 2, 2011, archived from the original on April 13, 2011 ; Retrieved April 13, 2011 .
  17. ↑ project goal. Website of the nanoTruck initiative , accessed May 30, 2012.
  18. ↑ Nanotechnology in concrete terms. Website of the nanoTruck initiative , accessed May 30, 2012.