In today's world, new materials have become a key word, and the hottest word is "graphene". In recent years, graphene is even hotter than carbon nanotubes. What kind of characteristics does it have, which makes the world pay so much attention? Graphene was discovered in 2004. Its composition is graphite, which has a hexagonal structure composed of carbon atoms. The thin film that looks like a honeycomb is only one atom thick, which is1/200,000 the diameter of a hair. It is the thinnest material you can imagine, which can be called two-dimensional material, that is, it is only long and wide, and its thickness can be ignored.

How is graphene made? The earliest graphene was stripped from graphite, and the process was very simple. After peeling with adhesive tape, a thin layer of graphite will be attached, and then the adhesive tape on the other side will be attached to separate it. The graphite on the tape will become thinner and thinner, and the graphite attached to the tape will become thinner and thinner. When it is only one atom thick, it is graphene. When people usually write with a pencil, it will be in pencil lead.

The method of sticking graphite with adhesive tape is the earliest mechanical stripping method of graphene. However, the finished graphene obtained by this method is unstable and uneven in thickness, so later, epitaxial growth method, chemical vapor deposition method, redox method, liquid phase stripping method and so on were invented one after another. What are the characteristics of graphene?

First of all, it is very thin, so it is very sensitive to changes in the surrounding environment. Even if only one gas molecule hits it, it will deform, thus changing the resistance. This characteristic can be used to manufacture sensor equipment. Because it is very thin, it only absorbs 2% light, which means it is almost invisible to the naked eye, and its high transparency can be applied to a series of new technologies, for example, it can integrate satellite navigation system on the windshield of a car, and even the display screen can be built into contact lenses.