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EXPLORATIONS - Nanotechnology: How the Science of the Very Small Is Getting Very BigBy Mario Ritter

Broadcast: Wednesday, February 08, 2006

(MUSIC)

VOICE ONE:

I'm Steve Ember.

VOICE TWO:

And I'm Faith Lapidus with Explorations in VOA Special English. Today we tell about


In the future, micro circuits and their tiny transistors2 will need to be made much smaller

one of the most important research fields in technology. It is called nanotechnology. It is the science of making things unimaginably small. But there is nothing small about the problems that scientists hope nanotechnology will solve.

(MUSIC)

VOICE ONE:

Nanotechnology gets its name from a measure of distance. A nanometer, or nano, is one-thousand-millionth of a meter. This is about the size of atoms and molecules4. Nanotechnologists work with materials this small.

Many experts credit the idea to physicist5 Richard Feynman. In nineteen fifty-nine, this Nobel Prize winner gave a speech. He called it There's Plenty of Room at the Bottom.鈥縩bsp; Mister Feynman discussed the theory that scientists could make devices smaller and smaller -- all the way down to the atomic level.


Richard Feynman

Although he did not use the word nanotechnology, the speech got many scientists thinking about the world of the very small. But for years this idea remained only a theory.

VOICE TWO:

At the time, no way existed to record structures the size of molecules. Not even electron microscopes could do the job. But as the nineteen eighties began, two researchers found a way. Gerd Binnig and Heinrich Rohrer worked at a laboratory in Zurich Switzerland. They worked for IBM, the American company International Business Machines.

They invented what they called a scanning6 tunneling microscope. This permitted scientist to observe molecules and even atoms in greater detail than ever before.

VOICE ONE:

Once they could see nano-sized structures, the next step for scientists was to find a way to create their own. By the middle of the nineteen eighties, 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 poly-carbon chains. Today, the result of carbon chemical engineering is everywhere -- in the form of plastic.

Scientists in the nineteen eighties wanted to create nano-structures from carbon atoms. In nineteen eighty-five, Robert Curl, Harold Kroto and Richard Smalley succeeded. They aimed a laser at carbon. This powerful light caused some of the carbon to become a 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 molecule3 of sixty atoms -- carbon sixty.

VOICE TWO:

Carbon sixty is a group of tightly7 connected carbon atoms that forms a ball. It is 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 molecular8 carbon can also appear with different numbers of carbon atoms. There is also carbon seventy, for example.

For their work, Robert Curl, Harold Kroto and Richard Smalley received the Nobel Prize in Chemistry in nineteen ninety-six.

(MUSIC)

VOICE ONE:

The next nano-structure development came in nineteen ninety-three. 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 someday 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.

In two thousand three, IBM announced that it had made the world's smallest light. Researchers used a carbon nanotube attached to a silicon9 base. They sent opposing electrical charges down the tube. The reaction between the charged particles produced an extremely small amount of light. IBM says the wavelength10 of light produced could be used in communications.

VOICE TWO:

Nanotubes appear to have many different uses. Scientists at the University of Texas at Dallas have developed a way to make a 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 is only fifty nanometers thick. That is about one one-thousandth the width of human hair.

The material is extremely strong and it carries electricity as well. Researchers think the nanotube material could be used to make car windows that can receive radio signals. They also believe it could be used to make solar electricity cells, lights or thin, moveable displays that show pictures like a television.

VOICE ONE:

Nano-materials are already being used in some products. For example, materials using mixtures of nano-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.

(MUSIC)

VOICE TWO:

Computer scientists hope developments in nanotechnology will help break barriers of size and speed. In nineteen sixty-five, electronics11 expert Gordon Moore recognized that computer chips, the engines that drive computers, would quickly grow in power.

He even thought of a way to measure this progress. He said researchers would double the number of tiny transistors on a computer chip about every two years. A transistor1 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 makers12. And Moore's law is one of the most talked about scientific barriers.

VOICE ONE:

In nineteen seventy-one, Intel created a computer chip containing two thousand three hundred transistors. In two thousand four, 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 two thousand two, 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 two thousand five, researchers for the company Hewlett Packard wrote about the problems of creating nano-transistors in the magazine Scientific American. They said transistors are often measured by the distance between the middle of two current-bearing wires. Their nano-wire transistor measured thirty-nanometers in size. They said the smallest transistor currently13 used in a computer is ninety nanometers. But making nano-transistors small enough to meet the demands of Moore's law may be years in the future.

(MUSIC)

VOICE TWO:

Although nanotechnology is exciting, there are concerns about the safety of super small structures. Scientists and environmental activists14 worry that nano-materials could pass into 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 suppress15 the growth of plant roots or could even harm the human body's ability to fight infection.

VOICE ONE:

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 government is expected to spend about thirty nine million dollars on research meant to investigate the health risks of nano-materials. But that is less than four percent of total government spending, which will be more than one thousand million dollars this year.

Many environmental groups say at least ten percent 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.

(MUSIC)

VOICE TWO:

This program was written and produced by Mario Ritter. I'm Faith Lapidus.

VOICE ONE:

And I'm Steve Ember. Join us again next week for Explorations in VOA Special English.


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点击收听单词发音收听单词发音  

1 transistor WnFwS     
n.晶体管,晶体管收音机
参考例句:
  • This make of transistor radio is small and beautifully designed.这半导体收音机小巧玲珑。
  • Every transistor has at least three electrodes.每个晶体管至少有三个电极。
2 transistors ff750796e6ff1fb40d6a8248a6485dc3     
晶体管( transistor的名词复数 ); 晶体管收音机,半导体收音机
参考例句:
  • In semiconductor receivers transistors take the place of vacuum tubes. 在半导体收音机中晶体管代替了真空管。
  • We often turn to this handbook for information on transistors. 我们常从这本手册查阅有关晶体管的资料。
3 molecule Y6Tzn     
n.分子,克分子
参考例句:
  • A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
  • This gives us the structural formula of the molecule.这种方式给出了分子的结构式。
4 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
参考例句:
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
5 physicist oNqx4     
n.物理学家,研究物理学的人
参考例句:
  • He is a physicist of the first rank.他是一流的物理学家。
  • The successful physicist never puts on airs.这位卓有成就的物理学家从不摆架子。
6 scanning 721aec3fbaaa868e9cdafb2012e98567     
v.扫描
参考例句:
  • He turns the bicycle about scanning the hand brakes. 他把一辆自行车转过来转过去,仔细研究那手刹车。 来自辞典例句
  • Scanning was first used in the transmission of pictures by telegraph. 最先应用扫描法是用电报传播图像。 来自辞典例句
7 tightly ZgbzD7     
adv.紧紧地,坚固地,牢固地
参考例句:
  • My child holds onto my hand tightly while we cross the street.横穿马路时,孩子紧拉着我的手不放。
  • The crowd pressed together so tightly that we could hardly breathe.人群挤在一起,我们几乎喘不过气来。
8 molecular mE9xh     
adj.分子的;克分子的
参考例句:
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
9 silicon dykwJ     
n.硅(旧名矽)
参考例句:
  • This company pioneered the use of silicon chip.这家公司开创了使用硅片的方法。
  • A chip is a piece of silicon about the size of a postage stamp.芯片就是一枚邮票大小的硅片。
10 wavelength 8gHwn     
n.波长
参考例句:
  • The authorities were unable to jam this wavelength.当局无法干扰这一波长。
  • Radio One has broadcast on this wavelength for years.广播1台已经用这个波长广播多年了。
11 electronics 5q0xB     
n.电子器件,电子学,电子技术
参考例句:
  • About 45000 people worked in electronics in Scotland.苏格兰约有4.5万人在电子行业工作。
  • He wants to brush up his knowledge of electronics.他想温习他的电子学知识。
12 makers 22a4efff03ac42c1785d09a48313d352     
n.制造者,制造商(maker的复数形式)
参考例句:
  • The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
  • The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》
13 currently SvMzI2     
adv.通常地,普遍地,当前
参考例句:
  • Currently it is not possible to reconcile this conflicting evidence.当前还未有可能去解释这一矛盾的例证。
  • Our contracts are currently under review.我们的合同正在复查。
14 activists 90fd83cc3f53a40df93866d9c91bcca4     
n.(政治活动的)积极分子,活动家( activist的名词复数 )
参考例句:
  • His research work was attacked by animal rights activists . 他的研究受到了动物权益维护者的抨击。
  • Party activists with lower middle class pedigrees are numerous. 党的激进分子中有很多出身于中产阶级下层。 来自《简明英汉词典》
15 suppress sFDyQ     
vt.压制,镇压,查禁,抑制,阻止
参考例句:
  • He continued to suppress the people and serve the imperialists.他继续镇压人民,为帝国主义效劳。
  • She was struggling to suppress her sobs.她拼命不让自己哭出来。

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