Q1

Nowadays terms like are floating around: nanosciences and nanotechnology. Please elaborate on the differences between these terms.

Answer 1

Nanosciences is the understanding of physical, chemical and materialistic behavior and properties of devices on small scale, in particular on some few hundred nanometers. These could be optical, magnetic, electronic, electrical or mechanical properties such as bending, strength etc., which are the basic ingredients of any science. The relation between nanoscience and nanotechnology is just like the relation between science and technology in general.

Nanotechnology would be the use and exploitation of the properties understood from nanoscience performed for technological purpose. If you make a transistor which measures 20nm across, then it is nanotechnology. People are already down with 50nm transistor by the way.

Nanotechnology is not a single discipline unlike chemical, mechanical, civil, and other things because it is not in that sense centered on some classical subject. It is an interdisciplinary field. In fact, each of the disciplines mentioned before has some relation to nano. For example in civil, you are looking at construction material, we can make nano cement because if I reduce the particle size or alignment, which is currently around microns, and bind disposal, then it turns out that the smaller particles would be more reactive and have more strength.

Or in electrical engineering if you are making some electrical device, for example a chip with nano scale components. If you are in chemical engineering you might be using nanotechnology for better catalysts to boost reaction rates or say in material science you are making some nano composite material, in that context some particles or some fibers may be dispersed in a matrix and those particles and fibers are small, and they give you much better toughness, this becomes the material science perspective.

Today nanotechnology has an impact on cosmetics, fabrics, materials, chemicals (catalysts for example) and a lot of other things implying that this is a very spread out technology which touches about every aspect of our life.

Q2

What are the various areas of study of nanoscience?

Answer 2

There is no human activity which is not attached with nano. The reason is simple: you can modify the property of any material that you are using today. For example, take a filter. Filters are used in air conditioners, cars, in industry, in medicine, or even in chemical/biological warfare. Now these filters can be made more efficient by applying nanotechnology, thus making smaller fibers that have larger surface area and are far more active in terms of removing contaminants. If you want to do purification of air or water, you can use the new filters.

Now if you look around yourself, you may use glass in window panes. With the help of nanotechnology, they can be made less rough, less brittle, tougher, or can be made more ‘smart’. Smartness means they can cut down the UV, other radiation or the light coming in depending upon the lighting condition inside. Thus in winters you can allow more light but in summers cut down light. Many of these things have already been done. Also you can take these glasses and add metallic nanoparticles to change the property.

If you take our skin and the cosmetics that are being used, a lot of them are already using nanotechnology. Many cosmetics that we use have an active ingredient that must penetrate through the pores of our skins which could be very useful.

Hence this particle could be a nano particle which could be the delivery vehicle in cases where a big particle cannot penetrate through the pores. In terms of delivery as posts of drugs, cosmetics or anything else like a beneficial therapy invasion, a lot of work can be related to nano technology. If you want to think of something that should go in and that should protect the skin from UV etc., they can again be made much better from nanoparticles rather than micro particles.

Nowadays plastic is also being nano tailored. All kind of polymers are getting affected. Metals are getting affected. So every day products, areas or any technology that exists today can be upgraded using nanoscience. Everything that we look around can be changed by nano.

Q3

Are there any environmental applications of the research that is going on in nanosciences?

Answer 3

We are trying to work on remediation, like we just discussed about filters, that is, purifying air, water, industrial waste, locking up all kinds of impurities. People are also studying the effect of nano materials on environment and health. It is not now that car exhausts have started generating nano particles; it was that we were not able to see them until now. People are now worried about how these nano particles spread, how they affect human body, where and for how long they remain etc. They are searching the man made, industrial and the natural sources of these nano particles and their influence. This is all part of nano science. Nano technology is now related to locking up these particles and preventing their spread by making new and efficient materials. These preventive materials are like shields for situations of extreme environment.

Q4

Please elaborate on nanolithography?

Answer 4

Lithography is a microfabrication technique. ‘Litho’ means stone and ‘graphy’ means to write on it. It is basically for producing structures and patterns on small scale. A derivative technique is photolithography. If you want to make a structure or device on a small scale, you can make it by utilizing this tool. Photolithography enables us to go to a scale of about a micron or a half of a micron. To go beyond this scale one needs other kinds of lithography which is not based on light but on X rays or electronic beams since they have smaller wavelength. The technology implementation is complex and expensive. Among the major changes that nanotechnology has brought is not in underlying principles or concepts but in the ways of implementation of these concepts.

Q5

Sir, please explain your research related to the dry eye syndrome.

Answer 5

A lot of people have dry eyes. People who suffer from dryness in eyes find it very painful. It is very difficult to manage this condition. Our eyes have a tissue called the cornea. Cornea is a very fragile tissue and directly interfaces with the outside world. Cornea is transparent and it is covered by a very thin film of water about 50 micrometers, which is called tear film. This film protects Cornea which is very vulnerable because bacteria are coming in all the time, invading it. If we didn’t have this water layer, then things would be coming in directly and hitting the cornea.

Skin cells are hydrophobic, i.e., they repel water whereas the corneal epithelial cells are hydrophilic, which means they like water. Without water they can’t survive, they get damaged or eroded leaving a hole in the cornea. In some people, this film is deficient in function and formation due to which cornea is exposed. So if eyes are not producing enough tears or even if they are producing enough tears but the film is not stable (like water on plastic surface comes out as a drop and doesn’t remain spread out) then we have a case of dry eye.

It’s a very serious condition affecting large number of people and there is no therapy addressing the underlining causes which, by the way, are not known for sure. Dry eye solutions are available but are expensive. Depending upon the severity of the problem one may have to use the solution 4-5 times daily. There is only management for the disease; there is no cure for it. Ours was the first chemical group that looked at this problem, to see if we could understand it in a different way.

The question we asked was: Are there some physiochemical aspects of the problem? Like the example I gave you about the water on a plastic surface, we thought that the hydrophobicity or the hydrophilicity of the cornea in different people in different conditions might have some relation to dry eye. Earlier I gave you an example why interdisciplinary and multidisciplinary research is needed. In this context, one must understand that a biologist or a doctor will never take up the dry eye problem as a chemical engineering problem as both their conditioning and their training is quite different.

If a person with a different background looks at the same thing, he may find a different meaning in it. There is no problem that classifies itself as a problem of chemical or mechanical engineering or biology, chemistry or physics. Every object or thing reveals a different aspect when looked at using a different perspective. What I mean to say is that different people depending upon their conditioning and training will look at the problem differently. At some time when I was doing surgery, we had to learn different setup skills and operate different tools. The methodology for tackling a problem is different in different areas, nomenclature included.

To work in an interdisciplinary manner one needs to understand the entire nomenclature, otherwise specialist conversations are hampered. In order to convey the problem to others you need to know it well. These are essential aspects of doing interdisciplinary research: one needs to appreciate and understand different tools of the trade and nomenclature.

Q6

Tell us something about Carbon MEMS.

Answer 6

Carbon MEMS are Micro Electrical Mechanical Systems made from carbon. Carbon is used because it is bio compatible. One can use Carbon MEMS as micro batteries by using an array of micro electrodes made of carbon. These batteries are light weight and can supply power for a longer time.