ISSUED BY: GCIS Communications Command Center
SOURCE: New Scientist
25February2011 5:00amEST
GCIS TECHNOLOGY UPDATE: NOW you see it, now it looks like something else. Radar images might never be the same again, thanks to an illusion device that can change an object's appearance. The technology could ultimately be used to hide military aircraft.
The device is part of a growing family of metamaterials - structures designed to steer light along curved paths. They have already been used to make objects appear invisible and to disguise a gap between two objects.
Wei Xiang Jiang and Tie Jun Cui's team at Southeast University in Nanjing, China, have created a structure that changes the way radio waves interact with a copper cylinder so that it appears to be composed of another material altogether.
Copper conducts electricity well and reflects incoming radio waves, giving it a bright radar signature. To alter this behaviour, the team built a device made of 11 concentric rings of circuit boards etched with small metal-lined channels that prevent electromagnetic waves reflecting away. Instead, they guide the waves in a direction that the researchers choose specifically to make the hidden object appear to have different electrical properties.
Placed around a copper cylinder, the arrangement created the illusion that the cylinder was made of a dielectric, a class of materials including porcelain and glass that do not conduct electricity and are more transparent to radio waves. (read full report)