Nanometer is the unit of length, and the symbol is nm. 1nm =1nm = 10 angstrom (billionth of a meter), which is about the length of10 atoms. Suppose that a hair has a diameter of 0.05 mm and is divided into 50,000 hairs on average in the radial direction, and the thickness of each hair is about 1nm.
The significance of nanotechnology-1
The so-called nanotechnology refers to a brand-new technology to study the motion laws and characteristics of electrons, atoms and molecules in the scale of 0. 1~ 100 nanometers. In the process of studying the composition of matter, scientists found that several or dozens of countable atoms or molecules isolated on the nanometer scale show many new characteristics, and the technology of manufacturing equipment with specific functions by using these characteristics is called nanotechnology.
The main differences between nanotechnology and microelectronics are: nanotechnology studies the realization of specific functions of equipment by controlling single atoms and molecules, and it works by using the fluctuation of electrons; Microelectronics technology mainly realizes its function by controlling the population of electrons and works by using the particle nature of electrons. The purpose of people's research and development of nanotechnology is to achieve effective control of the entire micro-world.
Nanotechnology is a comprehensive subject with strong cross-cutting, and its research content involves the vast field of modern science and technology. From 65438 to 0993, the International Steering Committee of Nanotechnology divided nanotechnology into six sub-disciplines: nanoelectronics, nanophysics, nanochemistry, nanobiology, nanofabrication and nanometrology. Among them, nano-physics and nano-chemistry are the theoretical basis of nano-technology, and nano-electronics is the most important content of nano-technology.
The significance of nanotechnology -2
Nanotechnology (nanotechnology)
Nano-technology is actually a technology to make substances with a single atom and molecule.
Judging from the research so far, there are three concepts about nanotechnology. The first is 1986, the molecular nanotechnology put forward by American scientist Dr. drexler in his book The Machine of Creation. According to this concept, we can make the machine of combining molecules practical, so that we can combine various molecules at will and make any molecular structure. The nanotechnology of this concept has not made significant progress.
The second concept defines nanotechnology as the limit of micromachining technology. That is, the technology of artificially forming nano-scale structures through nano-precision "processing". This nano-scale processing technology also makes the miniaturization of semiconductors reach the limit. Even if the existing technology continues to develop, it will eventually reach its limit in theory. This is because if the line width of the circuit is reduced, the insulation film forming the circuit will be extremely thin, which will destroy the insulation effect. In addition, there are problems such as fever and trembling. In order to solve these problems, researchers are studying new nanotechnology.
The third concept is put forward from a biological point of view. It turns out that organisms have nano-scale structures in cells and biomembranes.
The so-called nanotechnology refers to a brand-new technology to study the motion laws and characteristics of electrons, atoms and molecules in the scale of 0. 1~ 100 nanometers. In the process of studying the composition of matter, scientists found that several or dozens of countable atoms or molecules isolated on the nanometer scale show many new characteristics, and the technology of manufacturing equipment with specific functions by using these characteristics is called nanotechnology.
Nanotechnology is a comprehensive subject with strong cross-cutting, and its research content involves the vast field of modern science and technology.
Nanotechnology now includes nano-biology, nano-electronics, nano-materials, nano-mechanics, nano-chemistry and other disciplines. From micro-technology including microelectronics to nano-technology, people's understanding of the micro-world is getting deeper and deeper, and people's understanding and transformation level of the micro-world has reached an unprecedented height. Qian Xuesen, a famous scientist in China, also pointed out that the structure around nanometer and below nanometer is a key point in the next stage of scientific and technological development, which will be a technological revolution, thus causing another industrial revolution in 2 1 century.
Although there is still a long way to go before the application stage, developed countries such as the United States, Japan and Britain attach great importance to nanotechnology because of its extremely broad application prospects, and have made research plans and carried out related research.
Characteristics of nano-electronic devices
The performance of electronic devices manufactured by nanotechnology is much better than that of traditional electronic devices.
The working speed is fast, and the working speed of nano-electronic devices is 1000 times that of silicon devices, so the product performance can be greatly improved. Low power consumption, the power consumption of nano-electronic devices is only11000 of that of silicon devices. There is a lot of information storage. On a 5-inch CD less than the size of the palm of your hand, you can store all the books of at least 30 Beijing libraries. Small size and light weight can greatly reduce the size and weight of various electronic products.
Nanomaterials are "grumpy"
Nano-metal particles are flammable and explosive. Several kinds of nano-copper particles or aluminum particles will burn and explode violently when they meet air. Therefore, the powder of nano-metal particles can be used to make high explosives, and the solid fuel made of rockets can produce greater thrust. Using nano-metal particle powder as catalyst can accelerate the chemical reaction rate and greatly improve the yield of chemical synthesis.
Compressive and tensile properties of nano-metal blocks. The bulk metal material made of metal nano-particle powder is more than ten times stronger than ordinary metal and can be stretched several times. Used to make airplanes, cars and ships, the weight can be reduced to one tenth.
Nanoceramics are both rigid and flexible. Nano-ceramics are plastics made of nano-ceramic particle powder, which has brought a revolution to the ceramic industry. When nano-ceramics are applied to engines, cars will run faster and planes will fly higher.
The colored nano-oxide particles of nano-oxide materials can quickly change color under the irradiation of light or the action of electric field. Glasses used as soldiers to protect laser guns are perfect. Billboards made of nano-oxide materials will become more colorful under the action of electricity and light.
Nano-semiconductor materials are amazing. Nano-semiconductor materials can emit various colors of light, can be made into small laser light sources, and can also convert the absorbed light energy in the sun into electric energy. Solar cars and houses made of them have great environmental protection value. Various sensors made of nano-semiconductors can sensitively detect the changes of temperature, humidity and atmospheric composition, and will be widely used in automobile exhaust monitoring and atmospheric environmental protection.
Nanomedicine saves lives by combining drugs with magnetic nanoparticles. After taking, these nanoparticles can move freely in blood vessels and human tissues. Then a magnetic field is applied outside the human body to guide, so that the drug is concentrated in the diseased tissue, and the effect of drug treatment will be greatly improved. Nano-drug particles can also be used to block capillaries and "starve" dead cancer cells. Nanoparticles can also be used for cell separation in human body, and can also be used to carry DNA to treat gene defects. At present, magnetic nanoparticles have successfully separated cancer cells from normal cells in animals, and have been successful in clinical experiments to treat human bone marrow diseases, with broad prospects.
Nano-satellites will fly into the sky and cut and build materials freely according to people's wishes in a nano-sized world. This technology is called nano-machining technology. Nanomachining technology can integrate different materials. It not only has the function of a chip, but also can detect electromagnetic wave (including visible light, infrared light and ultraviolet light) signals, and at the same time can complete computer instructions. This is a nano-integrated device. Applying this integrated device to the satellite can greatly reduce the weight and volume of the satellite, make it easier to launch and reduce the cost.
Nanotechnology has entered people's lives.
On September 27th, experts from Institute of Chemistry, Chinese Academy of Sciences announced that they had successfully developed a new type of nanomaterial-superhydrophobic interface material. This material is super-hydrophobic and super-oleophobic, and can be made into textiles, without washing and without oil stains. Used for building surfaces, anti-fogging, anti-freezing, and avoiding manual cleaning. Experts said: Textile, building materials, chemicals, petroleum, automobiles, military equipment, communication equipment and other fields will inevitably lead to a "material revolution" caused by nanotechnology.
Thanks to the repeated efforts of scientists, the word "nano", which was unfamiliar to us a few years ago, now appears frequently in our sight.
Nanometer is a unit of length. 1 nm is equal to one billionth of a meter, and 20 nm is equal to one third of 1 hair. Since the 1990s, scientists all over the world have been engaged in a "nano-war": studying the laws and characteristics of the movement of electrons, atoms and molecules in the space from 0. 10 to 100 nanometers.
Of course, China is not far behind. 1993, the Beijing Vacuum Physics Laboratory of the Chinese Academy of Sciences manipulated atoms and successfully wrote the word "China", which indicated that China began to occupy a place in the international nanotechnology field and was at the forefront of international science and technology.
1998, Tsinghua University Fan Shoushan Group made gallium nitride into one-dimensional nanocrystals for the first time in the world. In the same year, scientists in China successfully prepared diamond nano-powder, which was praised by international publications as "transforming rice straw from carbon tetrachloride into gold-making diamond".
From 65438 to 0999, the research team led by Professor Xue Zengquan of Peking University assembled single-walled carbon nanotubes on the metal surface for the first time in the world, and assembled the thinnest probe with good performance in the world.
The research led by Dr. Cheng Huiming of Chinese Academy of Sciences combines high-quality carbon nano-materials, which is recognized as the most convincing achievement in the field of "hydrogen storage carbon nanotubes research" so far.
The research team led by Xie, a researcher at the Institute of Physics, Chinese Academy of Sciences, has developed the world's finest carbon nanotubes with a diameter of 0.5 nm, which is very close to the theoretical limit of 0.4 nm. The research team also successfully synthesized the longest carbon nanotube in the world, creating the "world's largest 3mm".
In the battle for the theme of "nano", Chinese people frequently show their faces, especially in the fields of carbon nanotube synthesis and high-density information storage, and China's strength cannot be underestimated.
With the efforts of the scientific community, "nano" is no longer a cold scientific vocabulary. It went out of the laboratory and penetrated into China people's daily necessities.
The living environment is becoming more and more environmentally friendly. The washability of traditional coatings is poor. Over time, the wall will become multi-toned. Now there is a new coating with nanotechnology, which not only improves the washability by more than ten times, but also has extremely low organic volatiles, no toxicity, no harm and no peculiar smell, effectively solving the problem that harmful gases caused by strengthening the seal of buildings cannot be discharged as soon as possible.
Long-term exposure of human body to electromagnetic waves and ultraviolet rays will lead to an increase in various morbidity or affect normal fertility. Now, high-efficiency radiation protection clothes with nanotechnology-high-tech computer work clothes and maternity clothes have come out. Scientists and technicians mix nano-sized anti-radiation substances into fibers to make a kind of "nano-clothing", which can block more than 95% of ultraviolet or electromagnetic radiation, and is non-volatile and insoluble in water, thus maintaining the anti-radiation ability for a long time.
Similarly, clothes made of chemical fiber cloth are prone to static electricity due to friction. Adding a small amount of metal nanoparticles in production can get rid of annoying static electricity.
White pollution has also encountered a strong challenge of "nano". Scientists use specially developed equipment to crush degradable starch and non-degradable plastics to "nanometer level" and then physically combine them. This new raw material can be used to produce 100% degradable agricultural plastic film, disposable tableware, various packaging bags and other similar products. The field experiment of agricultural plastic film for 4 ~ 5 years showed that starch was completely degraded into water and carbon dioxide within 70 ~ 90 days, while plastic became fine particles harmless to soil and air, and also completely degraded into water and carbon dioxide within 17 months. According to experts, this is a substantial breakthrough in completely solving white pollution.
From TV broadcasts, books and periodicals, and the Internet, we have learned a little about "nano", and "nano" is also quietly changing us.
Nano-accurate news
1959, richard feynman, a theoretical physicist, gave a speech at California Institute of Technology, proposing that it is possible to assemble atoms or molecules.
198 1 year, scientists invented the scanning tunneling microscope, which is an important tool for studying nanoparticles, from which we can see the atomic and molecular worlds.
1990 the first international nanotechnology conference was held in Baltimore, USA, and the form of nanotechnology was born.
199 1 year, carbon nanotubes were discovered by humans. Its mass is one-sixth of that of steel with the same volume, but its strength is 10 times that of iron, which has become the focus of nanotechnology research.
1993, after 1989, Stanford University in the United States eliminated atomic groups, and 1999, IBM in the United States expelled IBM, the Beijing Vacuum Physics Laboratory of China Academy of Sciences successfully manipulated atoms to write the word "China".
1997, American scientists successfully moved a single electron for the first time. This technology can be used to develop quantum computers with thousands of times higher speed and storage capacity than now. In the same year, new york University discovered that DNA can be used to manufacture nano-scale mechanical devices.
1999 Brazilian and American scientists invented the world's smallest "scale" when conducting carbon nanotube experiments, which can be called one billionth of a gram of an object, equivalent to the weight of a virus; Shortly thereafter, German scientists developed a "scale" that can weigh a single atom, breaking the record jointly created by American and Brazilian scientists. In the same year, American scientists realized an organic switch on a single molecule, which proved that electronic and computing devices can be developed at the molecular level.
Nano lace news
Listen to the sound of bacteria swimming
The Jet Propulsion Laboratory in Pasadena, California, USA, is currently developing a miniature microphone called "Nano Microphone". According to Businessweek, this kind of microsensor allows scientists to hear the sound of single bacteria swimming and the sound of cell fluid flowing. This kind of artificial nano microphone is made of fine carbon tube. It is precisely because of its small size and high sensitivity that this microphone can respond under very little pressure and let the researchers who monitor it get relevant sound information.
With this new product, scientists will be able to detect whether there is life on other planets and the growth and development of individual cells in organisms. The instrument development project has been approved by NASA, and NASA has also provided necessary technical support for the above laboratories.
"Nano Water" to Prevent Rape
According to People's Daily, a company in Guangzhou recently claimed that they had produced a kind of "nano-beads" made of medical stone and nano-special materials. As long as you put it in water, you can drink dirty water. Drinking "nano-water" for a long time can resist fatigue and lack of oxygen, and even "enhance women's ability to prevent gangsters from raping". It is understood that each box of nano beads needs 300 yuan, and it costs 3,800 yuan to buy a complete set of equipment (a water dispenser, a bucket of water and ten boxes of nano beads). The 76-year-old man surnamed He, persuaded by the salesman, not only believed in the magical effect of nano-water, but also took a fancy to the sales method of nano-water. The old man took out 220 thousand on his back, bought 75 sets of nano water units, and then waited for a monthly dividend of 20 thousand.
The economic inspection squadron of Dongshan Branch of Guangzhou Administration for Industry and Commerce investigated and dealt with the company on April 3. The nano-water, which is going to create a myth of science and technology, has no scientific appraisal description at all, and the company's nano-water packaging products have neither production license nor product certificate.