The researchers fabricated a unique material, known as a metamaterial, that acts as a lens to image scenes using fewer components than conventional detectors. Because of the properties of this man-made material, much of the additional equipment needed for conventional detector systems – like lenses, mechanical positioners and data storage or transmissions devices – are not required.
The material itself is a thin laminate with row-upon-row of tiny squares etched onto copper, each one of which is tuned to a different frequency of light. The material is flexible and durable enough to be attached to a wall, wrapped around corners or even laid on the floor like a rug, making it an inexpensive alternative for a variety of sensing applications.
The new system works with microwave light and produces two-dimensional images. The researchers are currently exploring moving the technology to three-dimensional capability in real-world settings.
The Duke researchers reported their findings Jan. 18 on-line in the journal Science. The research was supported by the Air Force Office of Scientific Research.
"By taking advantage of the unique properties of these metamaterials, we were able to create a system capable of microwave imaging without lenses or any moving parts, " said John Hunt, a graduate student working in the laboratory of senior investigator David R. Smith, William Bevan Professor of electrical and computer engineering at Duke's Pratt School of Engineering.
As an example, Hunt said that in many security situations, imaging systems move a single sensor device with a small aperture in front of the body of the subject, creating an effectively larger aperture. The scanning waves travel through clothing, but skin or other objects reflect the waves. The new device can scan the entire field at once, which would allow for faster and more efficient screening, the researchers said.
"Using conventional systems such as airport security cameras or collision-detection devices, you have to wait for a scan to complete before you can see an image, while the new system can scan an entire range at once," Hunt said.
The metamaterial is made of thousands of tiny apertures that can detect a wide spectrum of frequencies, allowing it to obtain a more global image of the scene, the researchers said.
"Each individual element of the metamaterial is tuned to narrow frequency," said Tom Driscoll, a post-doctoral fellow from the University of California – San Diego currently working in the Smith lab. "Together the individual elements scan the entire range to capture information about a scene very quickly."
"This system allows us to collect and compress the image during collection, instead of later, averting the detector, storage and transmission costs associated with conventional imaging of a scene," Driscoll said.
Other Duke members of the team were Alex Mrozack, Guy Lipworth, Matthew Reynolds and David Brady.
Richard Merritt | EurekAlert!
Transporting spin: A graphene and boron nitride heterostructure creates large spin signals
16.08.2017 | Graphene Flagship
From hot to cold: How to move objects at the nanoscale
10.08.2017 | Scuola Internazionale Superiore di Studi Avanzati
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).
The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
16.08.2017 | Physics and Astronomy
16.08.2017 | Materials Sciences
16.08.2017 | Interdisciplinary Research