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.
Earlier attempts by other researchers used metal rings and wires. "Ours is the first to do the cloaking of cylindrical objects with glass," Semouchkina said.
Her invisibility cloak uses metamaterials, which are artificial materials having properties that do not exist in nature, made of tiny glass resonators arranged in a concentric pattern in the shape of a cylinder. The "spokes" of the concentric configuration produce the magnetic resonance required to bend light waves around an object, making it invisible.
Metamaterials, which huse small resonators instead of atoms or molecules of natural materials, straddle the boundary between materials science and electrical engineering. They were named one of the top three physics discoveries of the decade by the American Physical Society. A new researcher specializing in metamaterials is joining Michigan Tech's faculty this fall.
Semouchkina and her team now are testing an invisibility cloak rescaled to work at mocrowave frequencies and made of ceramic resonators. They're using Michigan Tech's anechoic chamber, a cave-like compartment in an Electrical Energy Resources Center lab, lined with highly absorbent charcoal-gray foam cones. There, antennas transmit and receive microwaves, which are much longer than infrared light, up to several centimeters long. They have cloaked metal cylinders two to three inches in diameter and three to four inches high.
"Starting from these experiments, we want to move to higher frequencies and smaller wavelengths," the researcher said. "The most exciting applications will be at the frequencies of visible light."
So one day, could the police cloak a swat team or the Army, a tank? "It is possible in principle, but not at this time," Semouchkina said.
Her work is supported in part by a grant from the National Science Foundation.
Jennifer Donovan | EurekAlert!
Tracing aromatic molecules in the early universe
23.03.2017 | University of California - Riverside
New study maps space dust in 3-D
23.03.2017 | DOE/Lawrence Berkeley National Laboratory
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences