Researchers at the University of Texas have created a new super thin (0.15mm) invisibility cloak.
Until now, most of these cloaking systems involve the use of metamaterials. Metamaterials are materials with components which cannot be found in natural life.
Extremetech add “Usually, in the case of cloaking, materials that have a negative refractive index. A negative refractive index causes light to behave very oddly, allowing for the creation of superlenses that bend light beyond the diffraction limit, or cloaks that bend light in such a way as to make the covered object invisible. In this case, though, the researchers have eschewed metamaterials and instead fashioned an invisibility cloak out of conventional materials.
In theory, the Texan metascreen could also be used to cloak visible light — after all, visible light, microwaves, and infrared are all physically identical; they’re just waves that oscillate at different frequencies. “In fact, metascreens are easier to realize at visible frequencies than bulk metamaterials and this concept could put us closer to a practical realization,” says Andrea Alu, co-author of the research paper. The one problem is that their patterned material scattering technique inversely scales with wavelength — so, while it’s possible to hide an 18cm cylinder from 3.6GHz microwave radiation, they can only hide micrometer-scale objects from 400-800THz visible light. One micrometer is 0.001 millimeters; the width of a red blood cell is about six micrometers.”
The invisibility cloak, or ‘metascreen’ is made from a 66µm-thick sheet of copper that’s attached to a 100µm-thick sheet of flexible polycarbonate. The cloak is then attached to the object so that the cloak perfectly conforms to the object’s shape. The copper is patterned so that the scattered light from the cloak and the cloaked object cancel each other out.
You can read more via this research paper.
Kitguru says: We can see more breakthroughs coming soon in this field.