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Showing posts with label nano technology. Show all posts
Showing posts with label nano technology. Show all posts
June 26, 2011
June 25, 2011
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
May 17, 2011
carbon nanotubes
Some Applications of Carbon nanotubes.
Carbon nanotubes have diverse properties to be used in several work area. some of the developing applications are listed below.
1) Breast Cancer Tumor Destruction
Nanotubes are used to destroy the breast cancer tumors. They play like an antibody that is provided by the chicken. The antibody along with nanotubes is attracted to the proteins by the cancer cell in the body and nanotubes absorb laser beam killing the bacteria of tumor.
2) Wind Mill Blades
Nano tubes are also used in the wind mill blades because of there low weight to better wind and produce more electricity at faster rate.
3) Air Craft Stress Reduction
Nanotubes are also used in the space and air crafts to reduce the weight and stress of the various components working tighter. This has collectively reduced the weight of aircraft also.
carbon nanotubes
Properties of cabon nanotubes1. Nano carbon tubes have many unique properties high makes them superior then another nano structures discovered. The most dominant property of nano carbon tubes is their highest strength and stiffness in weight ratio. This wonderful property made scientists and researchers to consider nano carbon tubes is many fields of work.
2. Another useful characteristic of carbon nanotubes is their easy penetration is the cellular structures such as membrane. They look like smallest needles so it’s a possibility that they can function like a needle in cells.
3. Carbon nanotubes also have unique and outstanding electronic properties. Their electrical resistance changes randomly when existing molecules are attached with other carbon atoms. Organizations are utilizing this property of carbon nanotubes in building high performance sensors that can detect chemical vapors in the air even.
The above properties of carbon nanotubes are very useful for developing many extra ordinary machines in today’s world. For example NASA space craft centre is using carbon nanotubes to lighten the weight of their space crafts, medical researchers are utilizing the properties to directly deliver drugs the infected are from cancer and many more applications are still under development.
Structure of cabon nanotubes
Nanotubes have complex structure with sp² bonding. Each of its atoms is attached to its neighbors similar to the graphite atom. They form a sequence of layer when seen together. It has dual particle s in its structure which is divided into three classes. Specific terms are used to represent nanotubes classes according to the arrangements. The first one is known as “armchair” and present at the top left, the middle one is called “Zig Zag” and it has high symmetry. The third and last one is known as the “Chiral” which mean two mirror effect forms. This kind of structure is not easily understandable .Sufficient knowledge is required to properly understand the architecture of carbon nanotubes.
carbon nanotubes
What is Carbon Nanotubes
Carbon nanotubes are smallest molecule of graphite carbon with outstanding characteristics. They are considered to be the most strongest molecular structure which are known for their excellent electronics characteristics and because of that they are having high involvement in the industrial and commercial applications. Although they have high production cost but still they have huge market value.
Historical Background
Carbon nanotubes are found in 1985.Fullerenes played vital role in discovery of carbon nanotubes. The molecule discovered was named as C60. Its composition was similar to the graphite atom which was already present but this was a new composition because it has better properties then graphite. Later on 1990 it was proposed that C60 composition can be produced easily with the help of arc evaporation setups in all the laboratories. the famous Japanese researcher Sumio Lijima discovered the fullerene related carbon nanotubes in 1991.they were double layered tubes having diameter about 30nm and were closed form both ends. This was a major discovery which supported a lot in the electronics, mechanics and chemistry.
nano technology
Functional approach
Functional approach is used to build the objects regardless of their assembly or we can say on the basis of their functionality. Molecular electronics and synthetic chemical techniques are the example of functional approach.
Biomemtic approach
Biomemtic approach uses the biological methods and natural systems. Biomineralization is an example of the Biomemtic approach.
Working and Impact
Nano technology deals with the development of machines and new components at cellular scale. Its possibilities if viewed are limitless. Just simply imagine the devices and machines such as nano assembler which assembles the molecules at extremely fast and atomic level. We can see the depiction of nano technology almost every where in the world of fiction. As mentioned earlier nano technology has great impact in almost every filed of life. In literature we can see the example of smart paint which is used to change the color scheme of the color coated substances. This was formed in the result of implementation of nanotechnology. Other example of nanotechnology is the advancement in desktop of the computer system, pads are now imbedded into your wrists and you can easily carry your systems any where. It also has great impact in the computer world and artificial intelligence. It can be possible with the help of nanotechnology to engineer a computer at molecular scale.
Future of nanotechnology
Nanotechnology will be the major technology in development of every machine in coming years. The industries which provide advancements in the objects are already formulating the advancements in the nanotechnology. In the immediate future nanotechnology will be having variant applications in the modern world of sciences .most prominently in the filed of medicine, to introduce the colony of nanaomachines into patient’s body for repairing surgical wounds.
nano technology
Nanotechnology is the latest advancement in the world of sciences. It refers to the constructing and engineering of the systems ion function at very micro level or we can say at atomic level. It is used to advance the present systems by implementing the new concepts related to the particular field. It uses bottom up approach to build high performance products as compared to the current market products. it is also called as general purpose technology because it has a significant influence in almost all the industries of the society in different manner. Its diversify the current extensions of the developed objects to the next level of development.Description of working:
Nano is one billionth part of the meter in comparison to the normal carbon bond length. Complexity of engineering is increases but the Space between the molecules of an atom can be decreased or even removed with the help of nanotechnology. Two major approaches are used while working with nanotechnology
.
- bottom up
- top down
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