The essence of this development was that the cloak consisted of many beads. On one side of the cloak, these beads had built-in miniature cameras, with the help of which the image was transmitted to the beads on the other side of the cloak, which displayed the image. This created the illusion of invisibility. Therefore, one had only to look at a person from the other side, as all "invisibility" disappeared. Accordingly, the weight of such a development was comparable to the weight of a winter jacket.
Scientists went further and decided to develop a material with a negative refractive index of the rays. These materials (metamaterials) do not reflect light rays, they allow them to bend around themselves. Thus, the desired effect of invisibility will be obtained. After all, the visibility of an object is the reflection of light from it. If the light bends around the object, then it will not be visible. In 1997, they developed the first such material, which was later tested in laboratories. It consists of wire spirals that are laid out randomly to absorb light when falling at any angle. The material is already able to hide objects from visibility, but scientists are in no hurry to please the results achieved. The difficulty lies in the fact that the material must be adjusted to different light spectra, which makes it somewhat difficult to widely use this material.
Therefore, scientists can only continue to work, to reduce the particle size of the metamaterial to a few microns. To date, samples of such a metamaterial are used in military aviation for the invisibility of aircraft. The military is looking forward to the latest developments in the field of stealth materials!