Nanotechnology for Society and Sustainable Development
June 14, 2011
Dept of Social Work, Amritapuri
Dr. Shantikumar Nair, Dean-Research of Amrita Vishwa Vidyapeetham and Director of Amrita Center for Nanosciences delivered the key note address at the International Conference on Society, Technology and Sustainable Development organized by the Department of Social Work.
The central theme in Dr. Shanti’s address was the use of technology, especially nano technology, in the service of society and as a driver for sustainable development. The speech was widely acclaimed by delegates at the interdisciplinary conference.
“We learned so much,” remarked Dr. Catherine Dulmus, Associate Dean for Research and Director, Buffalo Center for Social Research, School of Social Work, University at Buffalo, State University of New York, after Dr. Shanti’s address.
“I tend to go mostly to social work conferences. I don’t think I have ever been to a conference where I learned anything about nano technology,” she added.
Included below are excerpts from Dr. Shanti’s talk.
I must confess that I am not from the field of social work. I am a material scientist. So what I will say can be taken more as a personal perspective. I have not published anything in the area of sustainability. For the past ten years, and especially during the last five at Amrita, I have worked in the area of nanotechnology. We are developing nanotechnology based products. I will offer my perspective of nanotechnology in terms of service to society and sustainability.
Today, nanotechnology is seen as a new revolution. We had the industrial revolution in the 1800s and the information revolution in the late 1900s. These were enabled by technologies such as the combustion engine; and the transistor and integrated circuit that led to the development of computers.
Towards the end of the previous century, biotechnology emerged as a promising new technology and now in this century, nano technology is being touted as a major new technology. It is too early to say whether these nascent technologies will lead to major revolutions, but certainly there is potential to make a major impact. It is not too early to look at their ramifications.
If we are looking at social responsibility and sustainability, the UN Millennium Development Goals need to be examined closely. This is what nations all over the world agree that technology should focus on; we should eradicate extreme poverty and hunger, reduce child mortality, combat diseases, ensure environmental stability, improve maternal health, ensure primary education for all, gender quality and empowerment of women.
Many experts now feel that in several of these areas there really is a potential for nanotechnology to make a contribution. Now if that is so, it is really a very significant technology that should be explored. But at the same time we have to understand what the limitations are and what questions of sustainability might arise.
So if we were to begin with talking about science, science is really just an exploration of the truth. For example, E=mc2. But if we stopped there, public funding for research would quickly evaporate. Because the public, while it is happy with the truth, also wants to see some benefit to society. So we come to technology, which is the application of science to societal benefits. But even stopping here is not desirable, as this conference so clearly recognizes. We have sustainability issues, we cannot deplete natural resources, the environment must not be damaged and we should mitigate risk to people from technology.
Nano science comes from going down to the nano scale. From that, a whole generation of nano technologies have been spawned. One has to examine the question of sustainability with respect to these. What are the problems that might arise with these technologies?
In nano technology, we are really talking about going down in size. We are not changing the material, we are not adding new elements to the periodic table. But simply by going down in size, so that the material has very high surface area, the properties of the material change. For example, if you reduce gold down to nano scale, it behaves as a semi-conductor and changes color. So although we are not adding new elements to the periodic table, we are sort of creating materials with new properties.
Exploiting this science of going down in size is what nano technology is all about – taking the science to products. So what are the products, what are the industries that nano technology has spawned?
Nano particle manufacturing is now a big business worldwide. These nano particles are incorporated in various devices for use in healthcare, etc. There are carbon nanotubes, graphene, those from metals, ceramics and polymers. Pretty much any material can be made into the nano form to bring about a new material. Not only in the form of a particle but also in terms of fibers. Mixing and matching these things gives us composites and scaffolds. These can be used to create highly miniaturized microsystems that have unbelievably high efficiencies and speeds.
What are some of the applications of nanotechnology for a sustainable world? That is, what applications address societal problems in a positive way? Let me list a few things that are really fairly major.
One is diagnosing diseases or screening for multiple diseases. Here nano particles and other nano scale devices can be extraordinarily efficient and far more so, than any regular or conventional diagnostic or screening devices.
We can now prepare nano particles in such a way that they attach only to cancerous cells. So even a single cell turning cancerous, can be detected. Healthy cells do not attract these nano particles, which are like robots that go searching specifically for diseased cells.
Not only for diagnosis, diseases can also potentially be treated in a better way. This has not yet come into common use, but many clinical trials are ongoing. And would make a huge difference in the way many diseases are treated.
We can put medicine inside nano particles, this will then preferentially kill only the cancer cells. All this work is ongoing in our labs. We have already shown very effective and highly selective killing of cancerous cells without damaging other tissue. These results are leading to the tremendous development of new medicines that have a high therapeutic value. What is important to keep in mind is that they are inexpensive, so treatment cost can also be reduced.
Regenerative medicine is another area of application. For example, one might have a heart attack, and the heart tissue might become damaged. Normally it is impossible to regenerate heart tissue, but with nanotechnology you can. A scaffold is created, we put basically stem cells in there, they differentiate into cardiomyocytes, and create healthy heart tissue externally or extra corporeally.
With nano structured scaffolds, we find much more efficient regeneration of tissue than which is possible with conventional scaffolds. So nanotechnology might play a huge role in our ability to regenerate tissue. One can regenerate brain tissue, liver tissue, pancreatic tissue. This, if shown to be effective, would make a huge impact on society.
Yet another application is water purification. Thousands of children in India and other countries are dying because of contaminated water. We are now developing nano filtration membranes that can filter out bacteria and viruses very efficiently, and in a way that no conventional water filter can. This may potentially provide a solution to the problem of clean water.
In our labs, we are testing nano particles of zinc oxide. These kill bacteria very effectively; they behave as anti-bacterial agents. If we use conventional zinc oxide, nothing happens. So you have a technology that in the nano scale provides a lot of additional features, like helping obtain clean water.
We are also testing fibrous materials made from polymers. We work with nano pores 100,000 times thinner than the human hair. These are very effective, when it comes to filtering out bacteria, viruses and other micro contaminants. They behave as fantastic membranes depending on how the fibers are functionalized.
Finally, with nano materials we may have a chance to solve the energy problem, if we are successful in some of the research that is currently going on. We know the problem with combustion energy, where we are depleting fossil fuels. Why not use batteries? But that cannot be a solution either. If we convert all the one billon plus vehicles in this world, so that they all run on lithium batteries, that is not sustainable, either. We would exhaust almost all the lithium that there is in the world.
Also, current technologies use excessive amounts of rare earths. Each Prius car uses 15 kg, the global demand is 150,000 tons for rare earths. So conventional energy sources do have their limitations in terms of sustainability.
We have a program looking at the nano technology applications in solar cells. Solar energy is one of the most plentiful forms of energy. The challenge has been to tap into it. Nano materials offer an opportunity to tap into it effectively because research shows that when the scale of certain materials is reduced, conductivity increases, leading to a much higher energy efficiency.
Silicon cells are the standard in solar cells. But they have 16% efficiency and they are expensive. As such, they are not yet competitive with the currently used fossil fuels.
However, if we use nano solar, we can actually reduce the cost by almost one third. By using nano scale powders, for instance, efficiency can be improved, by creating highly conductive films. By using new nano materials like graphene and carbon nano tubes, that have a very high energy density and power density, there is a lot of hope. If the energy density or the power density of current batteries is increased in a substantial way without using very expensive materials that are not sustainable, then we might have a solution.
We are working on solar cells that use nano structured thin films. These are titanium nano tubes. These tubes actually take the electrons generated from the sun and very efficiently transport them to the positive side, giving rise to very efficient extraction of energy. These are storage cells. We have combined graphene which is a very highly conductive nanomaterial with polymers that are deposited on to it, to form nano rod like structures, and we can get energy storage in terms of capacitance, of very high values that are very difficult to achieve with conventional materials.
So if we can generate electricity cheaply and more efficiently, if we can store the energy more efficiently and more inexpensively, we are looking at completely changing the face of how we live today. If we can get out of our dependence on fossil fuels through such innovative approaches, where efficient generation of power and storage of power is possible, then definitely we are reaching some of the UN Millennium Development Goals with this technology.
It is my personal perspective that nano particles based solar cells are far better than the current silicon cells, competitive with fossil fuels and hydroelectric power. Thin film and nano particle based batteries are much better and more efficient than current lithium batteries. And we can combine these storage and generation devices to build solar panels that work at night.
What are the sustainability issues?
In the area of health, there is the question of toxicity. A lot has been said about whether nano particles are really safe. If you bring materials down in scale, what are the issues? There has been a tremendous amount of work in this area. I think that the scientists working in development of nano technology based products, have learned from the mistakes made in the past. They are taking a careful look at toxicity issues.
We ourselves are a Center for Nano Toxicology under the Government of India. At Amrita, we have a very comprehensive program to ensure that toxic nano particles are not being produced which would hurt people.
Besides this, we will have to look carefully at disposal and recycling of solar panels and nano technology based batteries. When their life is over, we have to make sure that these items can be disposed off and recycled properly. We do not want potential nano particles being introduced into the atmosphere or contaminating the ground water.
So these are the issues we need to look at. Environmental contamination by nano particles is going to be something that will have to addressed. But I can assure you that in my exposure to the technology and my experience as a scientist, I know these are being addressed carefully even now because we have learned from mistakes in the past.