A group of Chinese military researchers have developed an invisibility cloak like in the Harry Potter films. It can hide ground military targets from spy radar satellites.
As quoted from the South China Morning Post, hiding objects from sophisticated military radars is difficult because they can detect weapons or infrastructure that are not visible to ordinary cameras.
Advanced military radar is also not like a satellite telescope that only works during the day, because it can produce clear photos at night.
Researchers at the Air Force Technical University in Xian, Shaanxi, China say the new material for the cloak is very light and flexible, but is enveloped in a circuit to alter the pattern of radar signals.
"A target covered in an invisibility cloak will appear like a flat piece of land. It is this unusual material's flexibility that can help make objects nearly invisible even to radar satellites," said lead researcher Xu Hexiu.
In a paper published in the Journal of Infrared and Millimeter Waves last month, it was stated that the invisibility cloak had several layers. The top is a thin cloth in the form of a printed circuit that can manipulate electromagnetic waves.
Xu's team used a unique 3D printing technology that can draw circuits on a piece of soft cloth as thin as a human hair with extremely high precision.
The researchers then added more layers, including thin plastic and metal, to create a surface that could change the direction of the return signal to mimic the characteristics of flat ground.
"Many metamaterials have been developed to fool radar satellites, but none can move as freely and as widely as the new cloak we developed," Xu said.
When radar waves hit an uneven object, they bounce back in different directions. This allows the computer to know its size and shape by measuring signal differences.
According to estimates, camouflage technology can protect more than 80% percent of military targets from satellite detection and avoid enemy missiles. But China has not provided details on the technology of this invisibility cloak because it is part of a secret military program.