May 25, 2011

nano_tech

Fundamental concepts of nanotechnology
Concept of nanotechnology is based on the fact that nanometer is one billionth of a meter and when materials are decompose and rearranged at such smaller scale then their characteristics changes. Spacing between the atoms of the molecules of particular materials is 0.12-0.15 nm and many other cellular structures like bacteria are also small. It was considered that nanometer is the amount a man’s beard grows in the man time taken by him to raises the razor in his hand to remove the beard.

Main approaches
Two main approaches are used in nanotechnology.

--> Bottom up
--> Top down

In the bottom-up approach, materials and machines are developed from molecular or atomic components which assemble themselves chemically by recognizing the similar molecules or by the principles of molecular recognition. On the other hand in the top down approach, nano objects are constructed from larger components and entities without restricting their atomic scale control.


Material perspective

On of the fundamental concept which is the ground basis for nanotechnology is the material perspective. Before the advent of nanotechnology material was not seen atomically. Scientists started decomposing large materials to from new components from them. it has been observed that decomposition of a materials at nano scale changes its properties. For example scanning tunneling microscopy. Number of mechanical and physical phenomenas which appears when system size is decreased these affects are known as mechanical effect or quantum size effects. Where as the electronic characteristics of solids are altered with great decrease in particle size. This effect does not come into play by going from macro to micro dimensions of materials. but when micro to macro size reduction was performed this affect become dominant when molecular size of the particle is reached. Electrical, optical, and magnetic properties of the materials changed at nanoscale rearrangements

Nano Mechanics and bio materials
The concept of nanomechanics was also originated when new chemical properties of conductors and semi conductors were found. Nano materials empowered the production of new devices but at the same time it also opened the potential risks in their reactions with biomaterials. Materials exhibit different properties as they exhibited at macro level which enabled unique applications to take place for example opaque elements become transparent such as copper, insulators become conductor at nano scale treatment like silicon, solid can be converted into liquid at normal room temperature such as gold. Bottom line is that nanotechnology totally transformed the entire structure of any substance into new architecture.

Molecular perspective (simple to Complex)
Advanced chemistry has reached the level where it can produce molecules for almost every structure of the present world. these techniques are used to prepare wide range of chemical compounds such as polymers and pharmaceuticals but the extension of the control gives birth to the question that how these molecules could be reassemble into more advanced super molecular assemblies. Molecular self assembly in gradually evolving into supramolecular chemistry to make the new components which can reassembles themselves.


Molecular recognition
Another important concept is the molecular recognition which is one of the fundamental concepts of nanotechnology. Molecular rearranges them selves chemically by molecular recognition. There is special force that is present between molecules non covalent intermolecular force which supports the conformation of chemical similarity of molecules.


Overview of nanotechnology
There are many new concept which came into being as nanotechnology stepped into the world of technology such as mechanosynthesis and many new implicational researches such as nanaoelectronics, nanomechanics etc. at present latest machines are having nano arrangements in them. The most recent components that were developed are three distinct molecular devices whose motion is controlled from the desktop with changing voltage a nanotube nanomotor, a molecular actuator, and a nanoelectromechanical relaxation oscillator. Scientists are still seeking to explore the characteristics of materials by conducting advanced research in the nanotechnology

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