Nm is the abbreviation of nanometer, nanometer, also known as nanometer, one billionth of a meter, is the unit of measurement of length, and the international system symbol is nm.
1 nanometer = 10^-9 meters, like centimeters, decimeters and meters, is a unit of measurement of length.
Nanotechnology, also known as nanotechnology, is a technology that studies the properties and applications of materials with structural dimensions in the range of 1 nanometer to 100 nanometers. After the invention of the scanning tunneling microscope in 1981, a field was born to study the molecular world with a length of 1 to 100 nanometers. Its ultimate goal is to construct products with specific functions directly from atoms or molecules. Therefore, nanotechnology is actually a technology that uses single atoms and molecules within the range of matter.
Nanotechnology is a comprehensive subject with strong cross-cutting characteristics, and the research content involves a wide range of modern science and technology. Nanoscience and technology mainly include:
Nanosystem physics, nanochemistry, nanomaterials, nanobiology, nanoelectronics, nanoprocessing, nanomechanics, etc. These seven relatively independent but interpenetrating disciplines and the three research areas of nanomaterials, nanodevices, and nanoscale detection and characterization. The preparation and research of nanomaterials are the basis of the entire nanotechnology. Among them, nanophysics and nanochemistry are the theoretical basis of nanotechnology, and nanoelectronics is the most important content of nanotechnology.
In 1993, the first International Nanotechnology Conference (INTC) was held in the United States, which divided nanotechnology into six major branches: nanophysics, nanobiology, nanochemistry, nanoelectronics, and nanoprocessing. technology and nanometrics, promoting the development of nanotechnology. Due to the particularity, magic and broadness of this technology, it has attracted many outstanding scientists from all over the world to work hard on it. Nanotechnology generally refers to nanoscale (0.1 to 100nm) materials, design, manufacturing, measurement, control and product technology. Nanotechnology mainly includes: nanoscale measurement technology: detection technology of nanoscale surface physical and mechanical properties: nanoscale processing technology; nanoparticle preparation technology; nanomaterials; nanobiological technology; nanoassembly technology, etc.
Nano technology includes the following four main aspects:
1. Nanomaterials: When a substance reaches the nanometer scale, approximately in the range of 0.1-100 nanometers, the properties of the substance are Mutations will occur and special properties will appear. This kind of material that has special properties that are different from the original atoms and molecules, as well as from macroscopic substances, is a nanomaterial.
If it is only a material with a scale of nanometers and no special properties, it cannot be called a nanomaterial.
In the past, people only paid attention to atoms, molecules or the universe, and often ignored this intermediate field. This field actually exists in nature in large quantities, but the performance of this scale range was not recognized before. The first to truly realize its performance and reference the concept of nanometers were Japanese scientists. In the 1970s, they used evaporation methods to prepare ultrafine ions, and by studying its properties, they discovered that: an electrically and thermally conductive copper or silver conductor is made of After reaching the nanometer scale, it loses its original properties and shows that it neither conducts electricity nor heat. The same is true for magnetic materials, such as iron-cobalt alloy. If you make it about 20-30 nanometers in size, the magnetic domain will become a single magnetic domain, and its magnetism will be 1,000 times higher than the original. In the mid-1980s, people officially named this type of material nanomaterials.
Why does the magnetic domain become a single magnetic domain and the magnetism is 1000 times higher than before? This is because the individual atoms in the magnetic domain are not arranged very regularly, and there is a nucleus in the middle of the single atom and electrons rotating around it outside. This is the reason for the formation of magnetism. However, after becoming a single magnetic domain, the individual atoms are arranged very regularly, showing strong magnetism to the outside world.
This characteristic is mainly used in the manufacture of micro motors. If the technology is developed to a certain point and used to create magnetic levitation, it can create faster, more stable, and more energy-saving high-speed trains.
2. Nanodynamics: mainly micromachines and micromotors, or collectively referred to as microelectromechanical systems (MEMS), used for microsensors and actuators of transmission machinery, optical fiber communication systems, and special electronics Equipment, medical and diagnostic instruments, etc. use a new process similar to the design and manufacturing of integrated electrical appliances.
The characteristic is that the parts are very small, the etching depth often requires tens to hundreds of microns, and the width error is very small. This process can also be used to make three-phase motors for ultra-fast centrifuges or gyroscopes. In terms of research, it is also necessary to detect micro-deformation and micro-friction at the quasi-atomic scale accordingly. Although they have not yet truly entered the nanoscale, they have great potential scientific and economic value.
Theoretically: Micromotors and detection technology can be brought to the nanometer level.
3. Nanobiology and nanopharmaceuticals: For example, nanoparticle-sized colloidal gold is used to fix DNA particles on the surface of mica, and interdigitated electrodes on the surface of silicon dioxide are used to interact with biomolecules. Experiments, phospholipid and fatty acid bilayer planar biological membranes, fine structure of DNA, etc. With nanotechnology, self-assembly methods can also be used to place parts or components within cells to form new materials. About half of new drugs, even in the form of fine powders with micron particles, are insoluble in water; however, if the particles are in the nanometer scale (i.e., ultrafine particles), they are soluble in water.
When nanobiology develops to a certain level, nanomaterials can be used to make nanobiological cells with recognition capabilities, and they can absorb biomedicine from cancer cells and inject them into the human body, which can be used to kill cancer cells in a targeted manner. .
4. Nanoelectronics: including nanoelectronic devices based on quantum effects, optical/electrical properties of nanostructures, characterization of nanoelectronic materials, as well as atomic manipulation and atomic assembly, etc. Current trends in electronic technology require devices and systems to be smaller, faster, cooler, and smaller, which means faster response times. Cooler means that the power consumption of a single device is smaller. But smaller is not without limits. Nanotechnology is the final frontier for builders, and its impact will be huge.