ScienceDaily (Nov. 20, 2012) — A metamaterial invisibility cloak that can adapt to hide different sized objects is demonstrated by in Nature Communications this week. The findings represent a useful advance for more practical applications of metamaterial cloaking. The research is led by Yonsei University, Korea.
Metamaterials have already been shown to hide objects from electromagnetic waves by manipulating the light so that it appears to have not interacted with anything. However, these cloaks need to be redesigned and rebuilt if the shape of the object changes.
Kyoungsik Kim and colleagues now present a smart metamaterial that is able to adapt to changes in the object shape, so that a range of objects may be hidden by one cloak. The cloak is based on elastic materials, which enable it to deform around the object. At the same, the deformation alters its properties to maintain invisibility.
The team build and demonstrate cloaks for objects whose height varies over around 10mm, using microwave frequency light incident for a range of angles. They report that the object remains well hidden in all cases.
These smart metamaterial cloaks provide a new avenue to explore adaptable, real-world applications of cloaking that are not limited by the objects they hide.
(This follows up previous research – see this earlier article, reported on the same Science Daily website)
Scientists Create First Free-Standing 3-D Cloak
ScienceDaily (Jan. 26, 2012) — Researchers in the US have, for the first time, cloaked a three-dimensional object standing in free space, bringing the much-talked-about invisibility cloak one step closer to reality.
Whilst previous studies have either been theoretical in nature or limited to the cloaking of two-dimensional objects, this study shows how ordinary objects can be cloaked in their natural environment in all directions and from all of an observer’s positions.
Published Jan. 26 in the Institute of Physics and German Physical Society’s New Journal of Physics, the researchers used a method known as “plasmonic cloaking” to hide an 18-centimetre cylindrical tube from microwaves.
Here’s an interesting little article from a Star Trek sci-fi fan page regarding the subject.
A cloaking device is a form of stealth technology that uses selective bending of light (and other forms of energy) to render a starship or other object completely invisible to the electromagnetic spectrum and most sensors. It has been encountered in varying forms over the centuries.
Humanity’s earliest-known encounter with cloaking technology came in the year 1986 in San Francisco. Admiral James T. Kirk decloaked the Klingon Bird-of-Prey he was commanding to waylay and frighten some whale hunters from killing two humpback whales. (Star Trek IV: The Voyage Home)
One of humanity’s earliest exposures to cloaking technology was in April of 2151, when agents of the Suliban Cabal approached the starship Enterprise undetected and kidnapped a Klingon national named Klaang from the ship’s sickbay. The Suliban used cloaking devices on many of their ships, including the cell ships, stealth-cruisers and salvage ships. The Suliban’s cloaking technology had been given to them by their mysterious benefactor from the 29th century.