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Nanotechnology: The Next Big Thing Is Really Small

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This research paper deals with the basics of nanotechnology. Nanotechnology covers a wide range including fabrication of functional nanostructures with engineered properties, synthesis and processing of nanoparticles, supramolecular chemistry, self assembly and replication techniques sintering of nanostructured metallic alloys, use of quantum effects, creation of chemical and biological templates and sensors, surface modification and films. Along with the current, short term and long term applications of the nanotechnology, this paper also emphasizes on its interdisciplinary nature. The direct and the indirect threats from the molecular nanotechnology is explained stating the disadvantages of this recent technology. It is also concluded that if this technology is used properly then the world will be on a technology roller coaster.

1.    Introduction
“Imagine a world in which microscopic procreating robots are sent into the human body with the mission of detecting cancer cells, disassembling them out into the blood stream as waste products, and then imagine similar robots in the hands of a sinister force that decides to turn on entire continent into gray dust Science Fiction or reality?”

This can be possible with Nanotechnology. As Fact meets fiction, the reality of nanotechnology is in some important ways, far stranger than the fiction can imagine.
A Nanometer (nm) is one thousand millionth of a meter and a single human hair is around 80,000 nm wide. For comparison, a red blood cell is approximately 7,000 nm wide and a water molecule is almost 0.3nm across. People are interested in the nanoscale (which is defined to be from 100nm down the size of atoms i.e. approximately 0.2nm) because it is at this scale that the properties of material can be very different from those at larger scale Nanoscience is defined as the study of phenomena and manipulation of materials at atomic, molecular and macromolecular scales, where properties differ significantly from those at a larger scale similarly

2.    What is Nanotechnology?
Nanotechnology  is defined as the design, characterization, production and application of structures, devices and systems by controlled manipulation of size and shape at the nanometer scale (atomic, molecular and macromolecular scale) that produces structures, devices and systems with at least one novel/superior characteristic or property. It is direct control of materials and devices on a molecular & atomic scale. Nanotechnology thus covers a wide range including fabrication of functional nanostructures with engineered properties, synthesis and processing of nanoparticles, supramolecular chemistry, self assembly and replication techniques sintering of nanostructured metallic alloys, use of quantum effects, creation of chemical and biological templates and sensors, surface modification and films.

3.    Which Discipline background it belongs to?
Nanotechnology is not of one age, but of all ages and like wise it is not related to one subject but to many subjects particularly Biology, Chemistry, Physics, Engineering, Computer Science and Mathematics.
In physics the field of microelectronics is moving towards smaller feature sizes and is already    submicron widths.

 In chemistry improved Knowledge of complex systems has led to new catalyst, membrane sensor and coating technology which rely on ability to tailor structures at atomic & molecular levels. It also includes aerosol sciences and computer modeling.

 In biology, living systems have subunits with size between micron and nanometer scale and can be combined with non-living nano structured materials. Biotechnology and Medicine are the areas contributing to nanotechnology.

 In engineering the related areas to nanotechnology are precision engineering & materials science.

4.    Applications of Nanomaterials
Below we list some key current and potential short and long-term applications of nanomaterials. Most current applications represent evolutionary developments of existing technologies: for example, the reduction in size of electronics devices.

5.    Current Applications
a) Sunscreens and Cosmetics
Nanosized titanium dioxide and zinc oxide are currently used in some sunscreens, as they absorb and reflect ultraviolet (UV) rays and yet are transparent to visible light and so are more appealing to the consumer. Nanosized iron oxide is present in some lipsticks.
 b) Composites
An important use of nanoparticles and nanotubes is in composites, materials that combine one or more separate components and which are designed to exhibit overall the best properties of each component.
c) Clays
Clays containing naturally occurring nanoparticles have long been important as construction materials and are undergoing continuous improvement. Clay particle based composites – containing plastics and nano-sized flakes of clay are also finding applications such as use in car bumpers.
d) Coatings and Surfaces
Coatings with thickness controlled at the nano- or atomic scale have been in routine production for some time, for example in molecular beam epitaxy or metal oxide chemical vapor deposition for optoelectronic devices, or in catalytically active and chemically functionalized surfaces.
e) Tougher and Harder Cutting Tools
Cutting tools made of nanocrystalline materials, such as tungsten carbide, tantalum carbide and titanium carbide, are more wear and erosion-resistant, and last longer than their conventional (large-grained) counterparts. They are finding applications in the drills used to bore holes in circuit boards.

6.    Short -term Applications
a) Paints
Incorporating nanoparticles in paints could improve their performance, for example by making them lighter and giving them different properties. Thinner paint coatings (‘light weighing’), used for example on aircraft, would reduce their weight, which could be beneficial to the environment.  .
b) Remediation
The potential of nanoparticles to react with pollutants in soil and groundwater and transform them into harmless compounds is being researched.
c) Fuel Cells
Engineered surfaces are essential in fuel cells, where the external surface properties and the pore structure affect performance.
d) Displays
The huge market for large area, high brightness, flat-panel displays, as used in television screens and computer monitors, is driving the development of some nanomaterials.
 e) Batteries
With the growth in portable electronic equipment (mobile phones, navigation devices, laptop computers, remote sensors), there is great demand for lightweight, high-energy density batteries. Nanocrystalline materials synthesized by sol–gel techniques are candidates for separator plates in batteries because of their foam-like (aero gel) structure, which can hold considerably more energy than conventional ones.
f) Fuel Additives
Research is underway into the addition of nanoparticulate ceria (cerium oxide) to diesel fuel to improve fuel economy by reducing the degradation of fuel consumption over time.
g) Catalysts
In general, nanoparticles have a high surface area, and hence provide higher catalytic activity. Nanotechnologies are enabling changes in the degree of control in the production of nanoparticles, and the support structure on which they reside.

7.    Longer-term Applications (next 5-15 years)
a) Carbon Nanotube Composites
CNTs have exceptional mechanical properties, particularly high tensile strength and light weight. An obvious area of application would be in nanotube reinforced composites, with performance beyond current carbon-fiber composites.
b) Lubricants
Nanospheres of inorganic materials could be used as lubricants, in essence by acting as nanosized ‘ball bearings’. The controlled shape is claimed to make them more durable than conventional solid lubricants and wear additives.
c) Magnetic Materials
It has been shown that magnets made of nanocrystalline yttrium–samarium–cobalt grains possess unusual magnetic properties due to their extremely large grain interface area (high coactivity can be obtained because magnetization flips cannot easily propagate past the grain boundaries). This could lead to applications in motors, analytical instruments like magnetic resonance imaging (MRI), used widely in hospitals, and micro sensors.

d) Medical Implants
Nanocrystalline zirconium oxide (zirconia) is hard, wear resistant, bio-corrosion resistant and bio-compatible. It therefore presents an attractive alternative material for implants. It and other Nan ceramics can also be made as strong, light aero gels by sol-gel techniques. Nanocrystalline silicon carbide is a candidate material for artificial heart valves primarily because of its low weight, high strength and inertness.
e) Machinable Ceramics
Ceramics are hard, brittle and difficult to machine. However, with a reduction in grain size to the nanoscale, ceramic ductility can be increased. Zirconia, normally a hard, brittle ceramic, has even been rendered super plastic (for example, able to be deformed up to 300% of its original length). Nanocrystalline ceramics, such as silicon nitride and silicon carbide, have been used in such automotive applications as high-strength springs, ball bearings and valve lifters, because they can be easily formed and machined, as well as exhibiting excellent chemical and high-temperature properties.
f) Water Purification
Nano-engineered membranes could potentially lead to more energy-efficient water purification processes, notably in desalination by reverse osmosis. Again, these applications would represent incremental improvements in technologies that are already available.
g) Military Battle Suits
Enhanced nanomaterials form the basis of a state-of- the-art ‘battle suit’ that is being developed by the Institute of Soldier Nanotechnologies at MIT (USA).
 
8.    Threats from Molecular Nanotechnology(MNT)
Even moon has a spot in it, nanotechnology is no exception .The dangers posed by MNT are also nearly limitless, cheap, fast mass production would enable spasmodic arms races; improved smart materials could make current weapons systems much more capable, or permit creation of entirely new classes of weapons. Perhaps the most publicized danger from MNT is the so-called "gray goo" problem, where self-replicating nanomachines essentially out-compete the naturally occurring life forms on earth.

9.    Direct threats
State-based arms races. Intentional misuse of MNT will probably pose the greatest direct threat to national security. Molecular manufacturing will allow anyone with access to the technology to quickly and economically create weapons of virtually any description; the aspiring arms producer would only have to provide designs, power, and basic materials.
Individual-based arms races. States may not be alone in weapons-production activities. MNT-enabled personal manufacturing could allow production to shift from governments to small groups or individuals; this democratization of arms production is the darker side of personal fabrication. Perhaps the most frightening weapon of all-and thus no doubt natural aspirations for potential nano-hackers are the infamous self-replicating "gray goo" assemblers. Designing a "gray goo" replicator would be an extraordinarily complex undertaking, however, and would require solving a multitude of extremely difficult engineering challenges; accordingly, some have argued that such an effort would be either impossible or highly unlikely.
 Surveillance: An early application of MNT and NT will likely be inexpensive, yet advanced, micro-surveillance platforms and tools. Mass-produced, these disposable sensors could be used to blanket large areas, providing ubiquitous surveillance of the people within. Although obviously a battlefield concern, such surveillance could also be employed against any group or population, raising privacy and legality issues.

Environmental damage: Recently, however, nanotechnology is increasingly being seen as a potential environmental problem in its own right. Both NT and MNT are expected to produce large quantities of nanoparticles and other disposable nanoproducts, the environmental effects of which are currently unknown. This "nano-litter" is also small enough to penetrate living cells, raising the possibility of toxic poisoning of organs, either from the nano-litter itself or from toxic elements attached to the nanoparticles.
Indirect threats: Molecular nanotech will be a disruptive technology, giving "...little or no advantage to the entrenched leader of an earlier technological wave," and thus has the potential to radically upset the geopolitical playing field, posing powerful indirect threats to national security.

Economic. Essentially a highly advanced manufacturing process emphasizing distributed, low-cost manufacturing, MNT directly threatens economies heavily dependent on mass production. For example, China's economic growth depends on using mass human labor to produce inexpensive, high-quality goods; in 2004 it provided over US$18 billion worth of manufactured goods to the department store chain Wal-Mart. But what will happen to China's economy when Wal-Mart is able to use its own MNT-enabled fabrication facilities at home to produce higher quality goods at even lower cost? For that matter, when consumers are able to produce their own high-quality, low-cost, custom-designed products in their own homes, who will need Wal-Mart?
Social. Molecular nanotechnology's medical applications may present some of the greatest social and ethical challenges in human history. Issues of cloning, genetically modified crops, abortion have created political atomic bombs in recent years.NT offers a completely new level of control over the human body and its processes. Accordingly, MNT has been embraced by the transhumanist movement, which advocates using technology to intellectually, physically, and psychologically improve the human form from its current "early phase" to a more advanced "post human." Reactions to transhumanist concepts range from enthusiasm to indifference to outright fear and hostility.


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