B L Razdan
I do not quite know whether, while challenging the ‘growth is good’ mantra, in his study in the field of economics titled ‘Small is beautiful’, EF Schumacher, knew that the same concept if applied to the field of science will revolutionize the entirely world and beyond, even though there was convergence on the contextual theme of improving the lot of the world and the humanity at large. Just as Schumacher felt that small-scale solutions on a human scale would turn around what he saw as a trend towards consumption as an end in itself, the American physicist Richard Feynman expressed in his paper titled “There is Plenty of Room at the Bottom” wherein he described a process in which scientists would be able to manipulate and control individual atoms and molecules. Both of these thinkers place work in the context of wider lifestyle. At times, however, our task is to accept the inevitable rather than “solve a problem”.
Centuries of scientific research into the nature of matter that surrounded the mankind led to the discovery of atom as the smallest particle exhibiting the properties of an element and a molecule as the smallest particle exhibiting the properties of a compound that would be formed by the combination of atoms of the same or of different elements in a given ratio so as to endow the particular compound with its properties, both physical and chemical. But the never-ending scientific quest did not stop there. It broke the atom and discovered that the atom in turn comprised of tiny electrically charged and neutral particles rotating inside and that the number and nature of the charge of these tiny particles would determine the nature of the element these formed, be it gold, silver or simply oxygen. Why it took so long for the scientists to make these discoveries is because the effectiveness of their work was all along hampered by their inability to see the structure of these particles of the matter. However the development of powerful microscopes capable of displaying particles as small as atoms has allowed scientists to see what they are working with.
This also prompted the American physicist Richard Feynman to present a paper titled “There is Plenty of Room at the Bottom” at an American Physical Society meeting at the California Institute of Technology (CalTech) on December 29, 1959 wherein he described a process in which scientists would be able to manipulate and control individual atoms and molecules. This process envisaged by Feynman, in course of time – about a decade later – was given the name of “nanotechnology” by Professor Norio Taniguchi, while working on ultra-precision machining. However, it wasn’t until 1981, when, with the development of the scanning tunneling microscope that could “see” individual atoms, that the study of modern nanotechnology began.
What is nanotechnology? Broadly speaking, it is the understanding and control of matter at the nano-scale, at dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications. Encompassing nano-scale science, engineering, and technology, nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scale. So how small is “nano”? A nanometer is one billionth of a meter. A sheet of paper is about 100,000 nanometers thick. And there are 25,400,000 nanometers in one inch. To give you an idea of how small that is, it would take eight hundred 100 nanometer particles side by side to match the width of a human hair and a smoke particle thus measured is about 1,000 nanometers wide On a comparative scale, if a marble were a nanometer, then one meter would be the size of the Earth.
Nanotechnology holds a great promise for the future of the world in general and the human race in particular. This is because traditional chemistry, in contrast, works on a bulk scale. Chemical syntheses typically result in poor yields of desired products with many unwanted by-products. Using nanotechnology to synthesize chemicals could result in greater yield of the desired products and fewer by-products. It could also mean using a nano-structured catalyst in a traditional chemical reaction to improve the rate or yield of products.
Nanotechnology is not just about the size of looking at very small things, it is about structure, or how things are put together, arranged, or assembled. It is the ability to work – observe, manipulate, and build – at the atomic or molecular level. It produces materials and systems that exhibit novel and significantly changed physical, chemical, and biological properties because of their size and structure. When a substance consists only of clusters of a few hundred atoms, the laws of quantum mechanics influence dramatic changes in its mechanical, optical, and electronic properties. These properties include improved catalysts, tunable photo-activity, and increased strength. It is this manipulation of atoms and nanostructures that nanotechnology is all about.
For biologists, studying molecular-level structure and function is also nothing new. All the same by applying nanotechnology, the work of the biologists is significantly altered and considerably improved. Traditional biology involves the study of living systems, ranging from bacteria to beetles to humans. All of these organisms rely on nanometer-sized protein machines (molecular motors) to do everything from whipping flagella to flexing muscles. An application of nanotechnology would be isolating one of these molecular motors from a living system and using it to construct a nano-scale device. A nanotechnology derived molecular motor might be fueled by sunlight and produce a rotational force that could pump minute volumes of fluids (e.g. pharmaceuticals) or open and close valves in nano-mechanical devices. Nano-particles and other nano-structured materials are often synthesized using chemical methods. However, nanotechnology is fundamentally different from traditional chemistry because it deals with manipulation and physical control at the atomic level of chemicals. Synthesizing a chemical with nanotechnology could actually mean building it atom by atom. We should, however, not forget that Nanotechnology overlaps significantly with many traditional disciplines like chemistry, physics, and that of materials research. After all, as stated earlier, these are the fields that discovered the atom and understood its inner workings, developed the science of combining them in precise structures, and developed tools with which these nanostructures are probed and visualized.
The ability to see nano-sized materials has opened up huge possibilities in a variety of industries and scientific endeavors. Because nanotechnology is essentially a set of techniques that allow manipulation of properties at a very small scale, it has a variety of applications, the most important for human health being the delivery of drugs. Today, most harmful side effects of treatments such as chemotherapy are a result of drug delivery methods that don’t pinpoint their intended target cells accurately. Researchers have been able to attach special RNA strands, measuring about 10 nm in diameter, to nanoparticles and fill the nanoparticles with a chemotherapy drug. These RNA strands are attracted to cancer cells. When the nano-particle encounters a cancer cell it adheres to it and releases the drug into the cancer cell. This direct method of drug delivery has great potential for treating cancer patients while producing less side harmful effects than those produced by conventional chemotherapy.
The ability to create gears, mirrors, sensor elements, as well as electronic circuitry in silicon surfaces allows the manufacture of miniature sensors such as those used to activate the airbags used in cars. This technique, called MEMS (Micro-Electro Mechanical Systems), results in close integration of the mechanical mechanism with the necessary electronic circuitry on a single silicon chip, similar to the method used to produce computer chips. Using MEMS to produce a device reduces both the cost and size of the product, as compared to similar devices made with conventional methods. This is a stepping stone towards the manufacture of more such products replacing the traditional ones, once the manufacturers make necessary investments in the equipment needed to produce nano-sized features.
Researchers are working on developing a method called molecular manufacturing that may someday make the Star Trek replicator a reality. The gadget these folks envision is called a molecular fabricator; this device would use tiny manipulators to position atoms and molecules to build an object as complex as a desktop computer. It is believed that that raw materials can be used to reproduce almost any inanimate object using this method.
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