Nanotechnology is a comprehensive subject with strong cross-cutting, and its research content involves the vast field of modern science and technology. Nanotechnology mainly includes:
Nano-system physics, nano-chemistry, nano-materials, nano-biology, nano-electronics, nano-machining, nano-mechanics, etc. These seven relatively independent and interpenetrating disciplines and three research fields: nano-materials, nano-devices and nano-scale detection and characterization. The preparation and research of nano-materials are the basis of the whole nano-technology. 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.
Nano fiber
Nanofiber 1993, the first international nanotechnology conference (INTC) was held in the United States, which divided nanotechnology into six branches: nano-physics, nano-biology, nano-chemistry, nano-electronics, nano-processing technology and nano-metrology, which promoted the development of nanotechnology. Because of its particularity, magic and universality, this technology has attracted many excellent scientists all over the world to study it hard. Nanotechnology generally refers to nano-scale (0. 1- 100nm) materials, design, manufacture, measurement, control and product technology. Nanotechnology mainly includes: nanoscale measurement technology: nanoscale surface physical and mechanical properties detection technology: nanoscale processing technology; Preparation technology of nanoparticles; Nanomaterials; Nanobiotechnology; Nanoassembly technology, etc.
Nanotechnology includes the following four main aspects:
1. Nanomaterials: When a substance reaches the nanometer scale, which is about 0. 1- 100 nanometer, the properties of the substance will suddenly change and special properties will appear. This kind of material with special properties different from the original atoms, molecules and macroscopic substances is called nano-material.
If only nano-scale materials have no special properties, they cannot be called nano-materials.
In the past, people only paid attention to atoms, molecules or cosmic space, and often ignored this intermediate field, which actually exists in nature in large quantities, but did not realize the performance of this scale range before. Japanese scientists were the first to truly recognize its characteristics and introduce the concept of nano. In 1970s, they prepared ultramicro ions by evaporation, and found that a kind of conductive copper-silver conductor lost its original properties after being made into nano-scale, neither conducting electricity nor conducting heat. The same is true of magnetic materials, such as iron-cobalt alloys. If the size is about 20-30 nanometers, the magnetic domain will become a single magnetic domain, and its magnetism is 1000 times higher than the original. In the mid-1980s, people formally named this kind of materials as nanomaterials.
Why does the magnetic domain become a single magnetic domain, and its magnetism is 1000 times higher than the original one? This is because the arrangement of single atoms in a magnetic domain is not very regular, but there is a nucleus in the middle of a single atom surrounded by electrons, which is the reason for the formation of magnetism. However, after becoming a single magnetic domain, the single atoms are arranged regularly and show strong magnetism to the outside.
This characteristic is mainly used to manufacture micro-motors. If the technology is developed for a certain period of time and used to manufacture magnetic levitation, a faster, more stable and more energy-saving high-speed train can be manufactured.
2. Nano-dynamics: mainly micro-machines and micro-motors, or micro-electromechanical systems (MEMS), which are used as micro-sensors and actuators for transmission machinery, optical fiber communication systems, special electronic equipment, medical and diagnostic instruments, etc. It adopts a new technology similar to the design and manufacture of integrated appliances. The feature is that the parts are very small, the etching depth often needs tens to hundreds of microns, and the width error is very small. This process can also be used to manufacture three-phase motors, ultra-high-speed centrifuges or gyroscopes. In the research, micro-deformation and micro-friction at quasi-atomic scale should be detected accordingly. Although they have not really entered the nanometer scale at present, they have great potential scientific and economic value.
Theoretically, micro-motor and detection technology can reach nanometer level.
3. Nano-biology and nano-pharmacology: for example, dna particles are fixed on mica surface with colloidal gold with nano-particle size, and the interaction between biomolecules, double-layer planar biofilm of phospholipids and fatty acids, and the fine structure of dna are tested on interdigital electrodes on the surface of silica. With nanotechnology, you can also put parts or components into cells through self-assembly to form new materials. About half of the new drugs, even the fine powder of micron particles, are insoluble in water; However, if the particles are nanoscale (i.e. ultrafine particles), they can be dissolved in water.
When nano-organisms develop to a certain technology, nano-biological cells with recognition ability can be made of nano-materials, and the biomedical absorption of cancer cells can be injected into the human body for targeted killing of cancer cells. This is an old way of raising money.
4. Nano-electronics: including nano-electronic devices based on quantum effect, optical/electrical properties of nanostructures, characterization of nano-electronic materials, atomic manipulation and assembly. The current trend of electronic technology requires devices and systems to be smaller, faster, colder and smaller, which means faster response. Being colder means that a single device consumes less power. But smaller is not infinite. Nanotechnology is the last frontier of builders, and its influence will be enormous.
The development of history
The inspiration of nanotechnology comes from a speech by the late physicist richard feynman 1959 entitled "There is still a lot of room at the bottom". The professor who teaches at California Institute of Technology put forward a new idea to his colleagues. Since the Stone Age, all human technologies, from sharpening arrows to photoetching chips, have been related to cutting or fusing hundreds of millions of atoms at one time in order to make substances into useful forms. Feynman asked, why can't we assemble from a single molecule or even an atom from another angle to meet our requirements? He said: "At least in my opinion, the laws of physics do not rule out the possibility of making things atom by atom."
In 1970s, scientists began to put forward ideas about nanotechnology from different angles. 1974, scientist Norio Taniguchi first used the term nanotechnology to describe precision machining.
198 1 year, scientists invented the scanning tunneling microscope, an important tool for studying nanotechnology, which revealed a visible atomic and molecular world for us and played a positive role in promoting the development of nanotechnology.
1990,
Richard Feynman)IBM Scientists at almaden Research Center of IBM have successfully rearranged individual atoms, and nanotechnology has made a key breakthrough. They used a device called scanning probe to slowly move 35 atoms to their respective positions, forming three letters of IBM. This proves that Feynman is right, and the two letters add up to less than three nanometers long. Soon, scientists can not only manipulate individual atoms, but also "spray atoms". Using molecular beam epitaxy, scientists have learned how to make extremely thin special crystal films, and only one layer of molecules can be made at a time. This technology is used in modern manufacturing of computer hard disk read-write heads. Richard feynman, a famous physicist and Nobel Prize winner, predicted that humans could make smaller machines with small machines, and finally they would arrange atoms one by one according to human wishes to make products. This is the earliest dream about nanotechnology.
1990 in July, the first international nanotechnology conference was held in Baltimore, USA, marking the official birth of nanotechnology.
199 1 year, carbon nanotubes were discovered by humans. Their mass is one sixth of that of steel with the same volume, but their strength is 10 times that of steel, which has become the focus of nanotechnology research. Professor smalley, winner of the Nobel Prize in Chemistry, believes that carbon nanotubes will be the first choice for the best fibers in the future, and will also be widely used in ultramicro wires, ultramicro switches and nanoelectronic circuits.
1993, following 1989, when Stanford University's mobile atomic group "wrote" Stanford University's English, and 1990, when IBM expelled the "IBM" on the surface of nickel with 35 xenon atoms, the Beijing Vacuum Physics Laboratory of Chinese Academy of Sciences manipulated the atoms freely and successfully wrote the word "China", which marked the beginning of China's international nanotechnology.
1997, American scientists successfully used single electrons to move single electrons for the first time. It is predicted that after 20 17 years, a quantum computer with thousands of times higher speed and storage capacity will be successfully developed.
1999, Brazilian and American scientists invented the world's smallest "scale" when conducting experiments on carbon nanotubes, and its weight can reach 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.
By 1999, nanotechnology has gradually entered the market, and the annual turnover based on nano-products has reached 50 billion US dollars.
200 1, some countries have formulated relevant strategies or plans and invested huge sums of money to seize the strategic highland of nanotechnology. Japan has set up a research center for nanomaterials, which has incorporated nanotechnology into the research and development focus of the new five-year science and technology basic plan; Germany has established a nanotechnology research network; The United States regards the nano plan as the core of the next industrial revolution. The investment of American government departments in basic research of nanotechnology increased from $65,438+1160,000 in197 to $497 million in 2006. China also listed nanotechnology as China's "973 Plan" to develop vigorously, and gave strong support to its related industries.
application area
At present, the research and application of nanotechnology are mainly in the fields of materials and preparation, microelectronics and computer technology, medicine and health, aerospace and aviation, environment and energy, biotechnology and agricultural products. The equipment made of nano-materials has lighter weight, stronger hardness, longer service life, lower maintenance cost and more convenient design. Nano-materials can also be used to make materials with specific properties or materials that do not exist in nature, and to make biological materials and bionic materials.
1, nanometer is the unit of measurement for geometric dimensions, 1 nanometer = one millionth of a millimeter.
2. Nanotechnology has promoted the technological revolution.
3. Drugs made by nanotechnology can block capillaries and "starve" cancer cells.
4. If nano-integrated devices are used on the satellite, the satellite will be smaller and easier to launch.
Nanotechnology is a synthesis of many sciences, and some goals take a long time to achieve.
6. Nanotechnology, information science and technology and life science and technology are the mainstream of current scientific development, and their development will make human society, living environment and science and technology itself better.
7. Nanotechnology can observe the pathological changes and conditions of cancer cells in patients, so that doctors can prescribe the right medicine.
measuring technique
Nano-scale measurement technology includes: precise measurement of nano-scale size and displacement, nano-scale surface morphology measurement. There are two main development directions of nano-scale measurement technology.
One is optical interferometry, which uses interference fringes of light to improve the resolution of measurement. Its measurement methods include: dual-frequency laser interferometry, optical heterodyne interferometry, X-ray interferometry, F-P standard tool measurement and so on. It can be used for accurate measurement of length and displacement, and also for measurement of surface micro-morphology.
The second is scanning probe microscopy (STM), whose basic principle is tunneling effect based on quantum mechanics. Its principle is to scan the measured surface with a very sharp probe (or similar method) (the probe is not actually in contact with the measured surface), and measure the three-dimensional micro-stereoscopic morphology of the surface with the help of a nano-scale three-dimensional displacement positioning control system. It is mainly used to measure the micro-morphology and size of the surface.
biotechnology
Nanobiology is to study the structure and function of various organelles in cells on the nanometer scale. Study the exchange of matter, energy and information within cells and between cells and the whole organism. The research of nanobiology mainly focuses on the following aspects.
Great progress has been made in DNA research in three aspects: morphological observation, characteristic research and genetic modification.
Brain function research
The goal of the work is to find out the advanced neurological functions of human memory, thinking, language and learning and the information processing functions of human brain.
Bionics research
This is a hot research content of nanobiology. A lot of achievements have been made now. This is a promising part of nanotechnology.
The smallest motor in the world is a biological motor-flagella motor. It can rotate like a propeller to drive the flagella to rotate.
Nanometer ceramics
Nanometer ceramics. Motor is usually composed of 10 protein population, and its structure is like an artificial motor. It consists of stator, rotor, bearing and universal joint. Its diameter is only 3nm, the rotating speed can be as high as 15r/min, and the right turn and left turn can be switched in 1 μ s ... Acceleration or deceleration can be realized by using external electric field. The power source of rotation is the concentration difference of nitrogen and oxygen ions inside and outside the membrane supporting the motor in bacteria. Experiments prove that. The potential difference inside and outside the bacteria can also drive the flagella motor. Modern people are exploring to design an artificial flagella motor driver that can be controlled by potential difference.
Mitsubishi Corporation of Japan has developed a retina chip, which can simulate the function of human eyes in processing visual images. The chip is based on arsenic semiconductor. Each chip contains 4096 sensing elements. It is expected to be further applied to robots.
It is proposed to make molecular machines like rings and rods. Assemble them into circuit units of a computer. The unit size is only Inm, and it can be assembled into a subminiature computer with a volume of only a few microns, which can achieve the same performance as modern common computers.
In the manufacture of nano-structured self-assembled complex electromechanical systems, a big problem is the assembly of various components in the system. The more advanced and complex the system is, the more difficult it is to solve the assembly problem. Protein, DNA, cells, etc. All kinds of creatures in nature have extremely complex structures. Their generation and assembly are automatic. If we can understand and control the self-assembly principle of biological macromolecules, human understanding and transformation of nature will inevitably rise to a brand-new and higher level.
derivative product
robot
Nano-robot is a kind of "functional molecular device" that can run in nano-space, also known as molecular robot. The research and development of nano-robot has become a hot spot in the forefront of science and technology.
In 2005, many countries made relevant strategies or plans, and invested huge sums of money to seize the strategic highland of nano-robot, a new technology. A few days ago, the monthly magazine Robot Times pointed out that nano-robots have a wide range of potential uses, especially in the medical and military fields.
The emergence of every new technology seems to contain infinite possibilities. It won't be long before the magical nano-robots with molecular size will continue to enter human daily life. Professor Zhou Haizhong, a famous scholar in China, predicted in the article on robots published in 1990 that by the middle of the 20th century, nano-robots would completely change human labor and lifestyle.
Raincoat umbrella
Nano raincoat umbrella (conversion diagram)
Nano-raincoat umbrella is a combination of umbrella and raincoat. Nano-umbrella has three-fold umbrella and straight umbrella (in short, there are two options when collecting umbrella). Nano-raincoats can be transformed from nano-umbrellas. Nano-raincoats are different from ordinary raincoats because they can ensure that they are absolutely not wet from head to toe. Because of nano-materials, this umbrella can be dried completely at once. After the umbrella is transformed into a raincoat, this raincoat can be completely dried with a slight jump when worn.
waterproof material
On August 4th, 20 14, Australia made a groundbreaking T-shirt with newly invented fabrics. No matter how people try to soak it, this T-shirt can keep good waterproof performance.
This white T-shirt named Knight is 100% cotton. Although the surface looks unremarkable, its fabric is woven by hydrophobic nanotechnology, which makes this T-shirt effectively prevent most liquids and stains from being immersed. This T-shirt can be machine washed, and its waterproof function can withstand up to 80 cleanings. Its fabric has a natural self-cleaning function, and any stains attached to it can be scrubbed or washed with water.
Different from other waterproof applications containing chemicals, T-shirts imitate the natural hydrophobic properties of lotus leaves. The invention of this fabric may have a revolutionary impact on restaurants and cafes. In addition, this cloth can also be used in the medical industry or hospitals.
development trends
Advanced nanotechnology, sometimes called molecular manufacturing, is used to describe nano-engineering systems (nano-machines) at molecular scale. Numerous examples have proved that hundreds of millions of years of evolution can produce complex and randomly optimized biological machines. In the field of nanotechnology, we hope to use bionics to find a shortcut to make nano-machines. However, Eric Drexler and other researchers suggest that advanced nanotechnology may be based on the principle of mechanical engineering, although it will initially use bionics as an auxiliary means.
United States of America
At the end of 2003, the National Science Council of the United States approved the National Science Council's award to the National Nanotechnology Infrastructure Network (NNIN), which will be jointly established by three universities in the United States/KLOC-0 to support the national nanotechnology and education network system. The five-year plan implemented in 2004 1 month will provide comprehensive national skills to support the research and education of nano-science engineering and technology. It is estimated that at least $70 billion will be invested in the research fund in five years. The purpose of the program is not only to provide top-notch experimental instruments and equipment for American researchers, but also to train a group of researchers specializing in the most advanced nanotechnology.
1. The United States develops the latest nano-cell manufacturing technology.
Nanotechnology can produce particles smaller than human blood vessels. The National Institute of Standards and Technology (NIST) pointed out that a method of producing consistent self-assembled nanocells has been developed for the treatment of encapsulated compressed drugs. This technology can be applied to the packaging technology of drugs at present, which can ensure the dosage of drugs more accurately, and will be applied to the related technologies of cancer chemotherapy for further research in the future.
Nano-plan is the main axis of the research and development budget of the federal inter-ministerial conference in 2005, reaching 980 million US dollars.
2.2 progress. DNA detection chip
In 2004 1 month, HP officially released the nano-scale chip for rapid DNA detection. In 2004, the complex detection step of "DNA microarray" based on optical principle was adopted in DNA detection, and the HP team changed this complex step into a circuit chip. In production, the sensitive element of DNA detection chip is a kind of nanowire with a thickness of about 50 nanometers, which is made by electron beam lithography and reactive ion etching. However, from the commercial point of view, the result is too high, so the research team is developing a technology to make DNA detection chip components by using cheaper optical lithography technology.
3. Research on groundwater pollution control
Groundwater pollution is an important topic widely discussed in modern times. In modern times, the United States announced a nano-particle technology, in which the center of the particle is an iron core, and the outside is covered with multi-layer polymers, in which the inner layer is made of polymethyl methacrylate (PMMA) with excellent waterproof performance. PMMA) and the outer layer is coated with hydrophilic sulfonated polystyrene. Because the hydrophilic outer layer makes nanoparticles soluble in water, the inner waterproof layer can attract trichloroethylene, a pollution source. The iron core in nanoparticles leads to the splitting of trichloroethylene, which in turn makes this pollution source gradually split into non-toxic substances.
4. Start the cancer nanotechnology program.
In order to combine nanotechnology, cancer research and molecular biomedicine widely, the National Cancer Center (NCI) put forward the cancer nanotechnology plan, which will carry out interdisciplinary work through three aspects: out-of-hospital plan, in-hospital plan and nanotechnology standard laboratory. The plan presents six challenges:
Cancer prevention and treatment: develop nano-scale equipment that can deliver anticancer drugs and various anticancer vaccines.
Early detection and protein research: Develop an implantable device for early detection of cancer biomarkers, and develop a platform device that can collect a large number of biomarkers for massive analysis.
Imaging diagnosis: develop imaging equipment that can improve the resolution to identify a single cancer cell, and nano-equipment that can distinguish cells from different tissues in tumors.
Multifunctional therapeutic equipment: develop nano-devices with both diagnostic and therapeutic functions.
Cancer care and quality of life improvement: develop and improve the symptoms of pain, depression and nausea caused by chronic cancer, and provide an ideal drug delivery device.
Interdisciplinary training: training a new generation of researchers who are familiar with cancer biology and nanotechnology.
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