Nano Science and Nano Technologies

(Summary of TMH book on Science and Technology for UPSC CSE preparations)

1. Distinguish between NANO Science  and NANO technology
Nanoscience is the study of phenomena and manipulation of materials at atomic, molecular and macromolecular scales, whose properties differ significantly from those at a larger scale.

Nanotechnology is the design, characterisation, production and application of structures, devices and systems by controlling the shape and size at the nanometer scale.

2. What is the size of a Nano meter, the human hair, a blood cell and an atom? 385
One nanometer(nm) is one-billionth of a meter. 1 nm = 10-9 m.

A human hair is approximately 80,000 nm wide, a red blood cell is approximately 7000 nm wide, and atoms are below a nanometer in size.

3. What did Feyman mean when he said that there is plenty of room at the bottom?
By this, Feynman meant that there is immense possibility of manipulating materials at the scale of individual atoms and molecules. It is akin to the whole of the Brittanica Encyclopedia written on the head of a pin.

4. How is Nano technology useful in cells and batteries?
An increase in surface area (per unit mass) will result in an increase in chemical reactivity, making some nano-materials useful as catalysts to improve the efficiency of fuel cells and batteries.

5 . Give examples of Nano  technology  occurring naturally
Milk is a nanoscale celluloid. There are more sophisticated examples such as nano-sized and nano-structured proteins that control a range of biological activities such as flexing muscles, releasing energy and repairing cells. Nano-particles are also naturally created in the process of combustion and food cooking.

6. Distinguish between top down and bottom up technologies on Nano technology.
Top-down techniques involve starting out with a block of material, and etching or milling it down to a desired shape. Bottom-up involves the assembly of smaller sub-units (atoms or molecules) to make a larger structure.

7. Distinguish between Nano technology and Micro technology
1 micrometre (micron) is equal to 1000 nanometres. The application of micro-technology is generally far closer to the market as compared to nano-technology. Micro-technology has been commercially exploited for many years, such as in the production of small, powerful computers.

8. What are carbon Nano tubes?
Carbon nano-tubes (CNTs) were first observed by Sumio Iijima in 1991. They are extended tubes of rolled graphene sheets. They are of 2 types- single-walled (one tube) and multi-walled (several concentric tubes). They have novel physical and chemical properties. They are mechanically very strong and are very good conductors of electricity.

9. What is a fullerene?
In the mid 1980s, a new class of carbon material was discovered called carbon 60 (C60). These are spherical molecules about 1nm in diameter, comprising 60 carbon atoms arranged as 20 hexagons and 12 pentagons, which is the configuration of a football. Some applications of fullerene are production of miniature ball bearings to lubricate surfaces, drug delivery vehicles and in electronic circuits.

10. What are Dendrimers?
Dendrimers are spherical polymeric molecules, formed through a nano-scale hierarchical self-assembly process. There are many types of dendrimers. They are used in conventional applications such as coatings and ink.

They have a range of interesting properties. They can act as nano-scale carrier molecules and as such could be used in drug delivery. Dendrimers can assist environmental clean-up as they can trap metal ions, which could then be filtered out of water through ultra-filtration techniques.

11. Energy is equal to wave length or colour. What does this mean?
Energy is related to wavelength or colour. This means that the optical properties of the particle can be finely tuned depending on its size. Thus, particles can be made to emit or absorb certain wavelengths (colours) by controlling their size.

12. Describe some of the  applications  of Nano technology already in use.
Nano-particles are used in the production of carbon nano-tube based tennis racquets, burn dressings and dental fillings. Nano-sized titanium dioxide and zinc oxide are used in sunscreens, as they absorb and reflect the UV radiation. They are also used in composites, which are materials that combine separate components such that they have the best properties of each component.

Carbon fibers are used in polymers to enhance conductivity. A particular type of nano-composite is where nano-particles are used as fillers in a matrix, such as carbon black which is used as a filler to reinforce car tyres.

13. What are clay particles? What is their use?
Clays containing naturally occurring nano-particles have long been important as construction materials. Clay particles based composites – containing plastics and nano-sized flakes of clay- are used in car bumpers.

14. Describe in hundred words some of the future uses of Nano technology.
In the next five years, nano technology could be used in computer hard-disks, self-cleaning windows, better photovoltaic devices for renewable energy sources, anti-corrosion coatings and non-invasive molecular imaging in medicine.

Over the next 5-15 years, they could be used in semi-conductor lasers for telecommunication, high density data storage, better medical implants and artificially created organs and better sensors for pollutants.

14. What is the danger to human health from Nano technology?
There is evidence that suggests that some of the manufactured nano-particles could be more toxic per unit mass than larger particles of the same chemical. Also, it seems that nano-particles can penetrate cells more readily than larger particles. If nano-particles penetrate the skin, they might facilitate the production of reactive molecules that could lead to cell damage. There is also evidence to suggest that combustible nano-particles might cause an increased risk of explosion because of their increased surface area and potential for enhanced reaction.

15. Describe the social and ethical issues arising out of Nano technology in 100 words
The convergence of nano-technology with information technology could result in increased personal safety and security. It could also be equally used for covert surveillance, or for the collection and distribution of information without adequate consent.

As new forms of surveillance and sensing are developed, further research and expert legal analysis might be necessary to establish whether current regulatory frameworks and institutions can provide appropriate safeguards to individuals and groups in society. Bio-terrorism could get a boost with the fusion of nano-technology with chemistry. Nano-technology could even be used to re-engineer human beings.

16. What is the impact of Nano Technology on warfare 100 words
In the military context, nano-technology holds potential for both defence and offence. They could be used to produce more lethal weapons that are much harder to detect than the weapons that are currently being used. Mind-machine interfaces could enable pilots and soldiers to control high-tech weapons by thought alone. ‘Cognitive feedback helmets’ allow remote monitoring of soldiers’ mental state. Pulse weapons and other nuero disrupters could play havoc with enemy soldiers’ thought processes. New drugs could be produced which could enable soldiers to go without sleep for days, to suppress fear, or to repress psychological inhibitions against killing.

17. Describe India ‘s National Mission on Nano Science and Technology. 150 words.
In 2004, President Kalam organised a meeting of nano-science experts to devise a national mission plan. Its recommendations included spending US$22m each year for the next 5 years on 5 new national facilities specialising in complimentary areas of nano-technology and 10 mini-centres across the country.

The President also called for a dynamic task force to identify important national projects and set deadlines for achieving results in areas such as drug delivery systems for cancer and HIV/AIDS.

It is in this background that the GOI in 2007 approved the launch of a mission on Nano Science & Technology (Nano Mission). The New Millennium Indian Technology Leadership programme is also promoting two public-private collaborative ventures for developing nano-technologies that target drugs to exactly where they are needed in the human body.

A national center for nano-materials has been set up at the International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI) in Hyderabad.

18. What are the prospects of Nano Technology in India. 100 words
With the core competence of IITs and Indian R&D institutions in collaboration with international institutions and industries, we can create joint venture organisations for many nano-technology products in water, energy, agriculture, health-care, space and defence. But far greater investment is required for this. The Nano Mision may provide the required financial impetus. With the Government approval for this mission, research in nano-science and technology in India appears to be poised for a renewed take-off.


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