Basic meaning
A single bacterium is invisible to the naked eye, and the diameter measured by microscope is about five microns. For example, suppose that the diameter of a hair is 0.05 mm, and it is cut into 50,000 pieces on average in the radial direction, and the thickness of each piece is about one nanometer. That is to say, one nanometer is 0.00000 1 mm. Nanoscience and technology, sometimes called nanotechnology, is to study the properties and applications of materials with structural dimensions between 1 and 100 nm. The development of nanotechnology has led to many new disciplines related to nanotechnology. There are nano medicine, nano chemistry, nano electronics, nano materials, nano biology and so on. Scientists all over the world know the importance of nanotechnology to the development of science and technology, so all countries in the world spend a lot of money to develop nanotechnology in an attempt to seize the strategic highland in the field of nanotechnology. China held a seminar on nanotechnology development strategy in 199 1 year, and formulated the development strategy countermeasures. In recent ten years, China has made remarkable achievements in the research of nanomaterials and nanostructures. At present, China's achievements in the field of nano-materials science are higher than any other country in the world, which fully proves that China occupies a decisive position in the field of nano-technology. Nano-effect means that nano-materials have strange or abnormal physical and chemical properties that traditional materials do not have. For example, copper, which is originally conductive, is not conductive at a certain nano-scale boundary, while silicon dioxide and crystals, which were originally insulated, begin to conduct electricity at a certain nano-scale boundary. This is because nano-materials have the characteristics of small particle size, large specific surface area, high surface energy and large proportion of surface atoms, and their three unique effects: surface effect, small size effect and macro quantum tunneling effect. For solid powder or fiber, when its one-dimensional size is less than 100nm, it can be called nano-material. For ideal spherical particles, when the specific surface area is greater than 60m2/g, the diameter will be less than 100nm, reaching the nanometer size.
At present, the micro-scale of many materials is mostly in nanometers. For example, most semiconductor process standards are expressed in nanometers. Until June of 20 12, the latest CPU technology was 22nm.
Nanotechnology is a kind of science and technology that uses a single atom and molecule to make substances. It studies the properties and applications of materials with structural dimensions ranging from 0. 1 to 100 nm. Nano-science and technology is based on many modern advanced science and technology, and it is the product of the combination of modern science (chaotic physics, quantum mechanics, mesoscopic physics and molecular biology) and modern technology (computer technology, microelectronics and scanning tunneling microscope technology, nuclear analysis technology). Nano-science and technology will trigger a series of new science and technology, such as nano-physics, nano-biology, nano-chemistry, nano-electronics, nano-processing technology and nano-metrology.
applied range
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.
Content-containing nano-materials
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, and 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 will be 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.
Nanodynamics
Mainly micro-machinery and micro-motor, or micro-electromechanical system (MEMS), used in micro-sensors and actuators and 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.
Nanobiology and Nanopharmacology
For example, dna particles are fixed on the mother surface with colloidal gold with the size of nanoparticles, and the interaction between biomolecules, the double-layer planar biofilm of phospholipids and fatty acids, and the fine structure of dna are tested on the interdigital electrode 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.
Nanoelectronics
Including nano-electronic devices based on quantum effect, optical/electrical characteristics of nanostructures, characterization of nano-electronic materials, and 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.