An Invisibility Cloak Made of Glass
Elena Semouchkina
From Tolkien’s ring of power in The Lord of the Rings to Star Trek’s Romulans, who could make their warships disappear from view, from Harry Potter’s magical cloak to the garment that makes players vanish in the video game classic “Dungeons and Dragons, the power to turn someone or something invisible fascinates mankind. But who ever thought that a scientist at Michigan Technological University would be serious about building a working invisibility cloak?
That’s exactly what Elena Semouchkina, an associate professor of electrical and computer engineering at Michigan Tech, is doing. She has found ways to use magnetic resonance to capture rays of visible light and route them around objects, rendering those objects invisible to the human eye.
Semouchkina and colleagues at the Pennsylvania State University, where she is also an adjunct professor, recently reported on their research in the journal Applied Physics Letters, published by the American Institute of Physics. Her co-authors were Douglas Werner and Carlo Pantano of Penn State and George Semouchkin, who works at Michigan Tech and Penn State.
They describe developing a nonmetallic cloak that uses identical glass resonators made of chalcogenide glass, a type of dielectric material (one that does not conduct electricity). In computer simulations, the cloak made objects hit by infrared waves—approximately one micron or one-millionth of a meter long—disappear from view. (more…)
Beyond the Looking Glass - Toward Invisibility
While the researchers can’t promise delivery to a parallel universe or a school for wizards, books like Pullman’s Dark Materials and JK Rowling’s Harry Potter are steps closer to reality now that researchers in China have created the first tunable electromagnetic gateway.
The work, ‘A simple route to a tunable electromagnetic gateway’ is a further advance in the study of metamaterials, published today, Thursday, 14 August, in New Journal of Physics (co-owned by the Institute of Physics and German Physical Society). It has been published at http://stacks.iop.org/NJP/11/083012.
In the research paper, the researchers from the Hong Kong University of Science and Technology and Fudan University in Shanghai describe the concept of a “a gateway that can block electromagnetic waves but that allows the passage of other entities” like a “‘hidden portal’ as mentioned in fictions.” (more…)
Scientists Closer to Making Invisibility Cloak a Reality
J.K. Rowling may not have realized just how close Harry Potter’s invisibility cloak was to becoming a reality when she introduced it in the first book of her best-selling fictional series in 1998. Scientists, however, have made huge strides in the past few years in the rapidly developing field of cloaking. Ranked the number five breakthrough of the year by Science magazine in 2006, cloaking involves making an object invisible or undetectable to electromagnetic waves.
A paper published in the March 2009 issue of SIAM Review, “Cloaking Devices, Electromagnetic Wormholes, and Transformation Optics,” presents an overview of the theoretical developments in cloaking from a mathematical perspective. One method involves light waves bending around a region or object and emerging on the other side as if the waves had passed through empty space, creating an “invisible” region which is cloaked. For this to happen, however, the object or region has to be concealed using a cloaking device, which must be undetectable to electromagnetic waves. Manmade devices called metamaterials use structures having cellular architectures designed to create combinations of material parameters not available in nature. (more…)
Next Generation Cloaking Device Step Closer to Invisibility
Pictured is the new cloak with bump, left, and the prototype, right. Cloaking devices bend electromagnetic waves, such as light, in such a way that it appears as if the cloaked object is not there. Credit: Duke University
A device that can bestow invisibility to an object by “cloaking” it from visual light is closer to reality. After being the first to demonstrate the feasibility of such a device by constructing a prototype in 2006, a team of Duke University engineers has produced a new type of cloaking device, which is significantly more sophisticated at cloaking in a broad range of frequencies.
The latest advance was made possible by the development of a new series of complex mathematical commands, known as algorithms, to guide the design and fabrication of exotic composite materials known as metamaterials. These materials can be engineered to have properties not easily found in natural materials, and can be used to form a variety of “cloaking” structures. These structures can guide electromagnetic waves around an object, only to have them emerge on the other side as if they had passed through an empty volume of space. (more…)
Loading... 
