With the development of the aerospace industry, the space suspension technology in the simulated microgravity environment has become an important means of conducting related high-tech research.

The levitation technologies up to 2012 mainly include electromagnetic levitation, optical levitation, acoustic levitation, airflow levitation, electrostatic levitation, particle beam levitation, etc. Among them, the electromagnetic levitation technology is relatively mature.
Commonly used to call electromagnetic suspension (EMS). Its main principle is to use the eddy current generated by the high-frequency electromagnetic field on the metal surface to suspend the metal ball. When a metal sample is placed on a coil with a high-frequency current, the high-frequency electromagnetic field will generate a high-frequency eddy current on the surface of the metal material. This high-frequency eddy current interacts with the external magnetic field, causing the metal sample to be subjected to a Lorentz force. effect. Under a suitable space configuration, the direction of the Lorentz force can be made opposite to the direction of gravity, and electromagnetic levitation can be achieved by changing the power of the high-frequency source to make the electromagnetic force equal to the gravity. Generally, the alternating current passing through the coil is 10^4-10^6Hz.
At the same time, the Joule heat generated by the eddy current on the metal can melt the metal, so as to achieve the purpose of smelting metal without a container. As of 2012, in the field of space materials research, EML technology has played an important role in the study of crystal growth, solidification, nucleation and deep supercooling in microgravity and container-free environments.
As of 2012, there are three types of maglev in the world. One is the conventionally conductive magnetic levitation represented by Germany, and the other is the superconducting dynamic magnetic levitation represented by Japan. Both types of magnetic levitation require electricity to generate magnetic levitation power. The third type is China’s permanent magnet suspension, which uses special permanent magnet materials and does not require any other power support.