Towards the unknown world

Biotechnology, information science and nanotechnology will be the mainstream of the development of medical technology in the next first Century. What is the content of nanoscience and what benefits will it bring to human society? This magazine will show you the magic of nanomaterials.

Nanoscience is studied at 10 million meters (10). ^-7 1 billion to one meter (10) ^-9 The knowledge of movement and change of atoms, molecules, and other substances. The manipulation and processing of atoms and molecules in this scale is called nanotechnology. In this century, great efforts have been made to restore the movement of all kinds of matter in the universe to the level of motion and properties of atoms and molecules. The use of atoms and molecules to delineate the various forms of matter in the great universe has also been a great success. For example, molecular biology and molecular biology have been studied from the point of view of molecular structure and motion; laser has been invented on the basis of atomic spectroscopy research; large scale integrated circuits have been constructed on the basis of solid electron theory; optical fiber communication has been invented by the dissemination of light in solids. It can be said that atoms and molecules (size about 10) ^-10 Rice, as a starting point, has made great achievements in understanding and reforming the macro world. Now people can synthesize all kinds of drugs and produce all kinds of genetically modified foods. The emergence of cloned sheep is the most outstanding representative work. At the same time, the development of computers and networks based on large-scale integrated circuits has greatly promoted the development of science and technology, and even changed people's way of life. Online shopping has enabled women to travel around famous department stores without leaving home. However, when people try to push the modern science and technology forward, they encounter great obstacles. This is mainly because people have blind areas in their knowledge, or there is a crack in the mansion of human knowledge. On the side of this crack is the microscopic world with atoms and molecules as the main body, while on the other side is the macro world of human activities. The two world is not a direct and simple connection imagined by ordinary people, but rather a transitional area -- the nanoscale world. That is to say, when a combination of dozens of atoms, molecules or thousands of atoms and molecules together, it is different from the properties of individual atoms and molecules, and is also different from the properties of large objects. Sometimes this "combination" is called "supramolecular" or "artificial molecule", which is different from the normal atoms and molecules.This kind of "supramolecular" often has unexpected properties. However, when these "supramolecular" continue to grow or aggregate into large chunks in the usual way, the original peculiar properties will be lost. It looks like some little children. In addition, it is also found that in this new world, the laws of motion of electrons and atoms are completely different. For example, when we increase the number of components in large scale integrated circuits, it is assumed that the electrodes can be made up of several nanometers, tens of nanometers, and the operation speed and memory of chips can be increased tens of thousands of times. However, in fact, it is difficult to use the popular technology to achieve this. On the other hand, even if such a device is made, the movement of electricity in such a small component is different. All chips need to be designed according to the new principle. It is one of the main problems in nanoscience and technology to understand the new rules in the system composed of a small number of electrons, atoms or molecules and how to manipulate them.

Manipulating atoms: the left side shows that the needle tip of the scanning tunneling microscope is used to transport and manipulate 48 atoms on the surface of copper so that they can be arranged in circles. The outward propagation of some electrons on the circle decreases gradually, while the electrons propagating into the circle interfere with each other to form interference waves.In the right picture, the iron atoms are manipulated one by one with the tip of the scanning tunneling microscope, and the Chinese characters are arranged according to the wishes of the experimenters. The size of Chinese characters is only a few nanometers.