God of small things

EMERGING TECHNOLOGIES

Nanoscience and nanotechnology are two of the hottest fields in science, business and news. Foldable TV and computer screens, water-proof make up, the invisible cloak, flying cars, space travel for everyone, new tools to combat disease, new ways of delaying ageing and the elimination of poverty and hunger are all developments that nanotechnology can easily bring about.

Nanotechnology is the next big science of designing and building machines at the molecular and atomic levels. For the first time in human history, we are close to being able to manipulate the basic forms of all things, living and inanimate, take them apart and put them together in almost any way the mind can imagine. The sophistication with which scientists are learning to engineer matter at the nano scale is giving us unprecedented mastery over a large part of our environment. The world of the future will be defined by how we use this mastery.

There is absolutely no doubt that during the next few decades, nanotechnology will be a viable frontier and we will see several interesting applications of the same in our daily lives. These applications will cover almost all sectors of human endeavour including energy, agriculture and food, textile and paint industry, electronics, computers, batteries, fuel cells, cosmetology, biomedicine, defence, communications, robotics, etc. Nano is big business today. It is predicted that by 2015, nano-related goods and services would capture a market of $ one trillion in the United States alone, making it one of the fastest growing industries. In the near future, it would be even larger than telecommunication and information technology industry put together.

What’s a nanometer?

The ‘nano’ in Greek means dwarf. One nanometre (abbreviated as 1 nm) means one billionth of a meter. To get a sense of nano, a human hair has a diameter of 50,000 nm. A bacterial cell has a 500 nanometres width. The smallest thing visible to the unaided human eye has a width of 10,000 nm. Just ten hydrogen atoms put one after the other make one nanometer.

The question is why these incredibly small things are so important? Why is nanotechnology making news every day? At a nano-scale, the smallness of the assemblies of atoms renders totally novel and unique set of properties which emanate from quantum phenomena as well as the large surface-to-volume ratio of such systems. During the past few years, considerable progress is being made on large-scale synthesis of nanoparticles and nanosystems with reproducible set of properties and their possible integration with the meso and microsystems of the device world.

There are two widely used approaches to build nanosystems: top down and bottom up. As part of the top down approach, a big object is reduced to nano size by successively cutting it whereas, as part of the bottom up approach, atoms and molecules are collected to build a nanosystem. Currently inspired by natural processes, self-assembly has attracted a lot of research attention to build nanosystems. Self assembly has transformed the relations between chemistry, materials science and biology.

From beautiful snowflakes that form due to random aggregation of water molecules to the creation of a living organism, nature has found such efficient means of self assembly that, in contrast, human techniques like top down and bottom up are often crude.

Scientists in the field of nanoscience and technocrats in the field of nanotechnology are patiently trying to learn this process. Once this process has been mastered, the world will be flooded with nanomaterials and nanomachines.

Stronger and lighter...

Imagine materials that are hundred times stronger than steel, but weigh only a fraction as much. Think of computer chips that store trillions of bits of information but are no bigger than a head of a pin. Within the next few years, a laser-based nano surgeon will be developed which reaches the tumor deep inside the organ and kill it without any operation.

Medical nanobot will be available by 2030, and it can easily travel across the bloodstream and monitor all the biochemical reactions inside the body. Around 2060, nanofabricators will be developed, which will assemble atoms and molecules to manufacture anything right from food to refrigerator, clothes to washing machines and books to computers.

With the help of nanotechnology and nanotechnological products, it is possible to increase the efficiency of the use of raw materials and energy over the lifecycle of a product. This would reduce the emission of pollutants as well as energy consumption.

Nanotechnology can help in improving water quality also. In the future, the so-called inverse nanotechnology (techniques to remove nanoparticles) will play an important role in sewage treatment. Thus, agents of disease such as viruses can be removed from pre-treated sewage by using nanoporous membranes, thus preventing these agents from spreading into the environment.

Can improve medical science

Realisation of nanoscale machines would pave the way for novel devices and processes capable of revolutionising medicine, or of reducing resource consumption and environmental pollution in manufacturing processes.

This would bring enormous benefits in terms of human health and quality of life. However due to their size, nanoparticles can cross biological membranes, cells, tissues, and organs more readily than larger particles. When inhaled, they can go from the lungs into the blood system. There is growing evidence that some nanomaterials may penetrate intact skin, especially in the presence of surfactants or massaging or flexing of the skin and gain access to systemic circulation.

This aspect of nanotechnology is not yet fully addressed. More research in this direction is needed. Also the social implications of this technology are to be thoroughly discussed.
Nanotechnology blended with biotechnology i.e. nanobiotechnology has the potential to alter the very human race. Can this possibly be good? What is the technological, political or social stand in the way? Will this new scientific revolution be for better or worse?

Undisputedly, there is a considerable need for further research on the subject of nanotechnology.

(The writer is Associate Professor in Physics, Birla College, Mumbai)