What is nano?

Nanometer is a unit of length, originally called nanometer, which is -9 power meter (65438+ billionth meter) of 10. Nanoscience and technology, sometimes called nanotechnology, is to study the properties and applications of materials with structural dimensions ranging from 1 to 100 nm. As far as specific substances are concerned, people often describe things as thin as hair as. In fact, human hair is generally 20-50 microns in diameter, not thin. A single bacterium is invisible to the naked eye, and the diameter measured by a microscope is 5 microns, which is not too fine. At the extreme, 1 nm is roughly equivalent to the diameter of 4 atoms. Nanotechnology includes the following four main aspects:

1. Nanomaterials: When a substance reaches the nanometer scale, which is about 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 will be 1000 times higher than the original. In the mid-1980s, people formally named this kind of materials as nanomaterials.

Nano-dynamics, mainly micro-machinery and micro-motor, or micro-electromechanical system, is applied to micro-sensors and actuators of belt-driven 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.

13. nano-biology and nano-pharmacology, such as fixing dna particles on mica surface with nano-sized colloidal gold, doing experiments on the interaction between biomolecules with interdigital electrodes on the surface of silica, double-layer planar biofilm of phospholipids and fatty acids, and fine structure of dna. 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.

3. Nano-electronics, including nano-electronic devices based on quantum effect, nano-electronics.