NANO Science and NANO Technology
- Nano is Greek means “dwarf”. It refers to dimension in the order of magnitude of 10-9. A Nanometer denoted by the symbol ‘nm’ is a unit of length in metric system equal to one- billionth of a meter.The term Nanotechnology was coined by Tokyo Science University Professor Norio Taniguchi and its technological significance was promoted by Dr. K. Eric
- Nanotechnology proposes construction of new nanoscale devices that possess extraordinary properties as they are lighter, smaller and less expensive and more precise.Materials reduced to Nanoscale can show properties compared to what they exhibit on a macro- scale, enabling unique applications. For instance Copper which was malleable at macro scale loses its property at the new scale. Inert material like Platinum at macro scale becomes catalyst at Nanoscale. A stable material like Aluminium at macro scale becomes combustible at Nanoscale. Insulator material like Silicon at the macro scale becomes a good conductor at Nanoscale.
- Nano Science is an emerging area of science which concerns itself with the study of atoms, molecules & objects whose size is on nanometerscale (1 to 100m). Nanotechnology deals with structures sized between 1 to 100 nanometer in at least one dimension, and involve developing materials or devices within that size.
1.3 PROCESS AND RAW MATERIALS
- The two methods used in Nanotechnology are Top-down and Bottom-up approaches. Inthetop-down approach, Nano objects are constructed fromlarger entities. It is expensive andtime consuming. The bottom-up technique builds larger structure by linking atom by atom using special molecular assemblers.
Nano materials are classified into two types
- Organic consisting of Carbon Inorganic Nano materials consisting of metals and their The vastly increased ratio of their surface area to volume lead to altering physical, thermal and catalyst properties of Nanomaterials.
1.3.1 Carbon Nano Tubes (CNT)
- Carbon Nanotubes are allotropes of carbon with cylindrical nanostructure. Graphene (graphite) sheets are rolled to form cylindrical Their name is derived from their long hollow structure with the walls formed by 1 atom thick sheets of carbon called graphene. These sheets are rolled into specific discreetangles. The combination of rolling angle and radius determines whether the nanotube is a metal or semiconductor. There could also be single walled nanotubes (SWNT) and multi walled nanotubes (MWNT).
220.127.116.11 Unique properties
- CNTs are the strongest & stuffiest material on Earth in terms of tensile strength (UTS). UTS means maximum strength that a material can withstand while being stretched or pulled. It is hundred times stronger, yet six times lighter than
Electrical Conductance property
- CNTs are ideal components for electrical circuits. They can carry thousand times more electricity compared to same dimension of copper/ silver wire.
- CNTs are very good thermal conductors along the tube axis, but are good insulators laterally to the tube.
- CNTs are stable up to 2800° C in vacuum.
1.3.2 Nano composites
- Nano composites are materials created by introducing nanoparticles / CNT into the matrix of microscopic sample material and the resulting Nano composite may exhibit drastically enhanced
1.3.3 Nano sensors
- Nano sensors are biological / chemical sensors used to convey information about nanoparticles to the macroscopic
1.3.4 Nano crystals
- Nano crystals are crystalline particles with at least 1 dimension measuring less than 1000nm. Nano crystals are used by the manufactures of filters that refine crude oil into diesel fuel. Nano- sized crystals a term being registered trademark of Elenpharma International.
- Nanotubes are used to make tiny transistors of Carbon Nanotube that help in developing Nano circuits. This has led to further miniaturization of computers making them even faster and compact. Use of CNT has strongly increased the data storage density of hard disk making terabyte range possible. Replacing CRT by CNT will lead to production of displays with low energy consumption. CNT can be used as emitters with extremely high intensity for field emission displays.
1.4.2 Automobile and Aviation Industry
- Lighter and stronger CNTs are of immense use to aircraft manufactures leading to increased performance. CNTs are used in making Nano satellites in space crafts.Usage of lighter CNT makes the aircrafts fuel efficient and the size of equipments are also reduced.
- Nanotechnology will help in manufacturing stronger; yet lighter anti-scratch, rust-proof, automobile components. The increase in surface area of internal combustion engine due to use of CNT will make them fuel-efficient and reduce exhaust of Combustion Engine will also benefit from parts that are more heat resistant.Windshields / front window of automobile provided with CNT can be made to de-frost automatically by passing current through them. Use of CNT will increase the conversion efficiency of solar panels.
1.4.3 Textile Industry
- Nano fibres make clothes water and stain repellent.Nano fibres will be stronger than the strongest natural fibre spider silk. It can be used to make strong bullet proof jackets. Moreover fluorescent Nano fibres will provide different colours to the fabric.
1.4.4 Health and Medicine
- Nanotechnology application lead to a new branch of medicine called Nano medicine.Nano medicine helps in diagnosis of a disease, drug delivery, treatment and tissue engineering.
- Nano medicine has resulted in the formation of Nano scale diagnostic devices which are able to detect cancer, bacterial, viral infection. One such devices is Lab-on-a -chip through which blood or any tissue sample is made to pass through, then this device blocks defective part of abnormal cells by allowing normal cells to pass through. Lab-on-a-Chip requires extremely small fluid volume to less than a Pico litre (10-12l). This low consumption leads to less wastage and requires less volume of sample for diagnosis and lowers reagent cost. At the same time diagnosis / analysis is faster.
- Nanotubes can be used in the formation of Nano-sized drugs which will help in lowering overall drug consumption and side effects by depositing active agent at specific places in the body, thereby ensuring drug delivery with cell precision. This will improve the bio-availability of a drug which refers to the extent of drug absorption. This highly selective approach reduces cost and human suffering.
Cancer diagnosis and Treatment
- Nanotubes can locate the elements of cancer cells using gold Nano shells. Nano shells target to bind cancerous cells by conjugating antibodies to Nano shells surface by irradiating the area of tumour with an infrared laser which pass through flesh without heating it. The Gold Nano shell is significantly heated to cause death of cancer cells.
- Nanotube can help to repair damaged tissue through tissue engineering making healing faster. They use scaffold (Bio- degradable polymer such as polycaprolactone coated with collagen to promote cell attachment) similar purpose as extracellular matrix in natural tissue.
1.4.5 Nano Robotics
- This is the technique of creating robots / machines close to Nanoscale. These Nano – sized robots can navigate through human body, transport important molecules, manipulate microscope objects and communicate with the physician by way of miniature.
- These computer controlled Nano robots can be used in cancer detection and treatment. There is no depressing therapy as in the case of Radiation therapy which actually ends up destroying healthy cells than the cancerous ones.
- Nano robots will be able to distinguish between maligned or normal cells by checking their surface antigens. Thus is accomplished by the use of chemotactic sensors, which are keyed to specific enzymes on target
- Nano filtration under NT can be helpful for waste water treatment, producing safe and clean drinking water. It is used in desalination of water. The extremely small size of pores enables filtration of bacteria, protozoa and other infectious agents.
- Nano – particles of Iron oxide are extremely effective at binding and removing Arsenic from ground water, Lanthanum nanoparticles absorb phosphate from aqueous environments. Applying these in ponds effectively removes available phosphates as a result, prevents growth of algae. This will benefit commercial fish ponds which spend huge amount of money to remove
- Nanotube has the potential to revolutionize agricultural sector by becoming an integral part of Precision farming and through Rapid Disease Detection and enhancing the ability of plants to absorb nutrients. Precision farming is site-specific farm management to maximise output (crop yield) and minimise input (i.e. fertilizers, pesticides, herbicides) through monitoring environment variables and applying targeted action. Precision farming makes use of PC, GPS, remote sensing devices to measure highly localized environmental conditions, thus determining whether the crops are growing at maximum capacity and precisely identifying the nature and location of problems. One of the major role Nanotechnology enabled devices play will be the increased use of Nano sensors linked to GPS for real time monitoring. Nano sensors distributed throughout the field can monitor soil conditions and crop growth. Wireless sensors are already being used in certain parts of USA and Australia. By using centralised data to determine soil conditions and plant development, fertilizers and chemicals, water use can be streamlined to lower production cost potentially increasing production.
- Technologies such as Encapsulation and controlledRelease method have revolutionized the use of pesticides and herbicides. Nano- emulsion/suspension of nanoparticles which can be either water/oil-based contain uniform suspension of pesticide/ herbicidal nanoparticles. These can be easily incorporated in various media such as gels, creams, liquids etc. It can be used in the preservation of harvested products.
- Thus networked Nano sensors in precision farming will help in crop scouting, processing integration of spatial data through GIS which will help in decision-making,weed control, pest-control fertilizer application site-specific, precise and effective.
1.4.8 Consumer Goods
Packaging and food safety
- Nanotechnology will help develop smart packaging to optimize product shelf-life. A Nano composite coating process could improve food packing by placing anti-microbial agents directly on the surface of coated film. Nano composites could modify the permeation behaviour of foils by increasing their barrier properties including mechanical, chemical, microbial agents also improving heat resistant properties like silicate properties can reduce entry of oxygen and prevent exit of moisture.Silver nanoparticles import anti- microbial, anti-fungal, anti-viral properties to the packaged food material. NT can help detect contamination of food also. For example, Agro Micron Company has developed a Nano bioluminescent detection spray which contains a luminescent protein that has been engineered to bind to the surface of microbes such as Salmonella, E-coli.When binds it emits a visible glow, thus allow easy detection of contaminated food. The more intense the glow is, higher the bacterial contamination.
- Most prominent application of NT in the household is self- cleaning / easy to clean surface on ceramics or glasses. Nano ceramic particles have improved the smoothness and heat resistance of common house-hold materials such as flat iron.
- NT can be used in sunscreen creams importing them long- term stability and protection against UV rays. It can also deliver Vitamin E to the skin. E.g. Titanium oxide and Zinc.
1.5 IMPLICATIONS OF NT
- Significant environment health and safety, ethical and social issues might arise with the development in NT. The potential risks of NT are
1.5.1 Environmental issues
- NT may lead to Nano pollution, which includes all the waste generated by manufacturing of nanomaterials and the Nano devices. Due to its extremely small size, Nano waste can float in the air and might easily penetrate animal and plant cells causing undesirable effects.
1.5.2 Health Issues
- Nanoparticles being slowly degradable may accumulate inside the body and because of their large surface area may get absorbed into the surface of tissues which may affect regulation mechanism of enzymes and their proteins
1.5.3 Social issues/ Nano ethics
- Nanotechnology could worsen the division of rich and poor by creating Nano-divide. NT has the potential to determine the international relations through Nano-arms race as there is possibility of military applications of NT in biological and Chemical warfare.
1.5.4 Grey goo
- It is specific risk associated with speculative vision of molecular NT. It is hypothetical end- of-the world scenario involving molecular NT in which out-of- control self-replicating robots consumer all matter on earth while building more of themselves a scenario known as ecophagy or eating the environment.
1.6 INDIA’S POSITION IN NANOTECHNOLOGY
- India started its Nanoscience and Nano technology development program under its 10th 5 year plan and funds worth $250 million have been allocated for research & development.
1.6.1 Indian Initiatives:
- In India, a vision group headed by Prof C.N.R Rao (Chairman of Indian Science Advisory Council) has been entrusted with the task of formulating the NT policy $ 250 million amount has been allocated for the research and development activities in Nano science and Nanotechnology.
- Rao’s work on Nanotubes through which junction Nanotubes were developed at Jawaharlal Nehru centre for Advance Scientific Research, Bengal found earlier applications in IBM’s efforts to design world’s transistor. Indian Institute of Science (IISc), Bengaluru & IIT Mumbai currently leads the country’s effort in Nanotubes.
- The regional government of Karnataka is eager to promote Bengaluru as a global hub for NT as in the past it has promoted it as software hub.Sabeer Bhatia the Hotmailco-founder has proposed to build a Nano city in Chandigarh which may be regarded as the second Silicon Valley in