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One of the most important research fields in technology is called nanotechnology. It is the science of making things unimaginably small. Nanotechnology gets its name from a measure of distance. A nanometre, or nano, is one-thousand-millionth of a metre. This is about the size of atoms and molecules. Nanotechnologists work with materials this small. Many experts credit the idea to physicist Richard Feynman. In 1959, this Nobel Prize winner gave a speech. He called it ‘There’s Plenty of Room at the Bottom’. Mister Feynman discussed the theory that scientists could make devices smaller and smaller – all the way down to the atomic level. Although he didn’t use the word nanotechnology, the speech got many scientists thinking about the world of the very small. But for years the idea remained only a theory. At the time, no way existed to record structures the size of molecules. Not even electron microscopes could do the job. But as the 1980s began, two researchers found a way. Gerd Binnig and Heinrich Rohrer worked at the laboratory in Zurich Switzerland for IBM, the American company International Business Machines. They invented what they called a scanning tunnelling microscope. This permitted scientists to observe molecules and even atoms in greater detail than ever before. Once they could see nano-sized structures, the next step for scientists was to create their own. By the middle of the 1980s, scientists had increased their research on carbon. They were interested in the ability to use this common element to make nano-sized structures. Carbon had already been engineered in chemical reactions to make long-carbon chains. Today the result of carbon chemical engineering is everywhere – in the form of plastic. Scientists in the 1980s wanted to create nano-structures from carbon atoms. In 1985, Robert Curl, Harold Kroto and Richard Smalley succeeded. They aimed a laser at carbon. This powerful light caused some of the carbon to become gas. The scientists cooled the gas to an extremely low temperature. Then they looked at the carbon material that remained. They found, among several kinds of carbon, a molecule of sixty atoms – carbon sixty. Carbon sixty is a group of tightly connected carbon atoms that forms a ball. It’s a very strong structure. This is because all the atoms share any loose electrons that might take part in chemical reactions with other atoms. This kind of molecular carbon can also appear with different numbers of carbon atoms. There is carbon seventy, for example. For their work Robert Curl, Harold Kroto and Richard Smalley received the Nobel Prize in Chemistry in 1996. The next nano-structure development came in 1993. Japanese scientist Sumio Iijima of the company NEC developed carbon nanotubes. These nano-sized objects are really six-sided atomic structures connected to form a tube. They are extremely strong. Scientists believe that some day nanotubes could replace the carbon graphite now used to make airplane parts. Soon after this discovery, researchers started to think about using nanotubes to build extremely small devices.

Scientists at the University of Texas at Dallas have developed a way to make flat material, or film, out of nanotubes. The researchers create the super thin film by chemically growing nanotubes on a piece of glass. They use another piece of sticky material to remove the film of nanotubes from the glass. When the film is finished, it’s only fifty-nanometres thick. That’s about one-thousandth the width of human hair. The material is extremely strong and it carries electricity as well. Researchers think nanotube material could be used to make car windows that can receive radio signals. They also believe that it could be used to make solar electricity cells, lights or thin, movable displays that show pictures like a television. Nano-materials are already used in some products. For example, materials using mixtures of nono-materials are being used to make sporting goods like tennis balls and tennis rackets better. Soon nano-materials could be used to improve devices that reduce pollution released by cars. Similar technology could be used to warn of the presence of poisonous molecules in the air.

Computer scientists hope development in nanotechnology will help break barriers of size and speed. In 1965, electronics expert Gordon Moore recognized that computer chips, the engines that drive computers, would grow in power. He even thought of the way to measure this progress. He said researchers would double the number of tiny transistors on a computer chip about every two years. A transistor is a device that controls electrical current. That statement is known as Moore’s law. It has proved correct for more than forty years. Mister Moore would go on to help start the company Intel, one of the world’s leading computer chip makers. And Moore’s law is one of the most talked about scientific barriers. In 1971 Intel created a computer chip containing two thousand three hundred transistors. In 2004 Intel made a chip with five hundred ninety-two million transistors. But current technology has reached its limit. The next jump to one thousand million transistors will require new discoveries in nanotechnology. Researchers are trying to solve the problems of creating nano-sized transistors. In 2002 IBM announced that it had created the world’s smallest transistor based on the element silicon. IBM said the transistor was four to eight nanometers thick. In 2005 researchers for the company Hewlett Packard wrote about the problems of creating nano-transistors in the magazine Scientific American. Their nano-wire transistor measured thirty-nanometres in size. They said the smallest transistor currently used in a computer is ninety nanometres. But making nano-transistors small enough to meet the demands of Moore’s law may be years in the future.

Although nanotechnology is exciting, there are concerns about the safety of super small structures. Scientists and environmental activists worry that nano-materials could pass in to the air and water causing health problems. There is reason for concern. A study by NASA researchers found that nano-particles caused severe lung damage to laboratory mice. Other studies suggest that nano-particles could suppress the growth of plant roots or could even harm the human body’s ability to fight infection. The Environmental Protection Agency says there is not much known about the effects of nano-structures in the environment. This is because the laws of physics do not work in the same way at the level of the extremely small. The EPA recognizes that this could mean that there are unknown health risks involved in nanotechnology. The American government is expected to spend about 39 million dollars on research meant to investigate the health risks of nano-materials. But that is less than four per cent of total government spending. Many environmental groups say at least ten per cent of that total is needed. They say private industry needs to spend more on safety research. And, they say, the government needs to develop rules for nano-materials, which are already being made in hundreds of places around the country.

Дата добавления: 2014-10-15