(Press-News.org) WASHINGTON, June 15, 2021 -- Optical cloaking allows objects to be hidden in plain sight or to become invisible by guiding light around anything placed inside the cloak. While cloaking has been popularized in fiction, like in the "Harry Potter" books, researchers in recent years have started realizing cloaks that shield objects from view by controlling the flow of electromagnetic radiation around them.
In the Journal of Applied Physics, by AIP Publishing, researchers from the Toyota Research Institute of North America examined recent progress of developing invisibility cloaks that function in natural incoherent light and can be realized using standard optical components, part of ongoing research over the last two decades.
Invisibility cloaks potentially have a broad array of applications in sensing and display devices in warfare, surveillance, blind spot removal in vehicles, spacecraft, and highly efficient solar cells. The researchers examined blind spots that occur in vehicles, such as the windshield pillars, the stanchions that frame windshields.
"We are always looking for ways to keep drivers and passengers safe while driving," said author Debasish Banerjee. "We started exploring whether we could make the light go around the pillar so it appeared transparent."
Advances in metamaterials, engineered complexes of metals and dielectrics for manipulating electromagnetic waves, have opened up the possibility for realizing optical cloaks around an object by making incoming light bypass it.
Perfect optical cloaking requires the total scattering of electromagnetic waves around an object at all angles and all polarizations and over a wide frequency range, irrespective of the medium. This has not yet been achieved.
However, by simplifying the invisibility requirements, innovative work with spherical transformation cloaks, carpet cloaks, plasmonic cloaks, and mantle cloaks in narrowband microwave, infrared, and optical wavelengths has been accomplished over the last two decades.
"One of the real challenges is that we have to optimize optical elements around an object so that phase relationships are preserved," said Banerjee.
For optimization, artificial intelligence and machine learning may help resolve certain challenges. Algortihms can help solve the necessary inverse design problem in the context of practical cloaking devices.
These can be powerful tools to predict and analyze the optical responses of these devices or detectors without time-consuming and expensive simulations, which may raise the possibility of intelligent invisibility that is adaptive to movements, shapes, and the environment.
With the fast development of both AI-aided design and additive manufacturing capabilities, it is foreseeable that flexible cloaks that could function effectively at all incident angles with a high cloaking ratio and a wide field of view could be realized and mass-produced at low cost and high efficiency.
INFORMATION:
The article "Optical cloaking and invisibility: From fiction toward a technological reality" is authored by Kyu-Tae Lee, Chengang Ji, Hideo Iizuka, and Debasish Banerjee. The article will appear in the Journal of Applied Physics on June 15, 2021 (DOI: 10.1063/5.0048846). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/5.0048846.
ABOUT THE JOURNAL
The Journal of Applied Physics is an influential international journal publishing significant new experimental and theoretical results in all areas of applied physics. See https://aip.scitation.org/journal/jap.
WASHINGTON, June 15, 2021 -- Alzheimer's disease is predominant in elderly people, but the way age-related changes to lipid composition affect the regulation of biological processes is still not well understood. Links between lipid imbalance and disease have been established, in which lipid changes increase the formation of amyloid plaques, a hallmark of Alzheimer's disease.
This imbalance inspired researchers from Aarhus University in Denmark to explore the role of lipids comprising the cellular membranes of brain cells.
In Biointerphases, by AIP Publishing, the researchers report on the significant role lipids may play in regulating C99, a protein within the amyloid pathway, and disease progression. Lipids have been mostly overlooked from a therapeutic standpoint, likely because ...
A tickle in the nose can help trigger a sneeze, expelling irritants and disease-causing pathogens. But the cellular pathways that control the sneeze reflex go far beyond the sinuses and have been poorly understood. Now, a team led by researchers at Washington University School of Medicine in St. Louis has identified, in mice, specific cells and proteins that control the sneeze reflex.
"Better understanding what causes us to sneeze -- specifically how neurons behave in response to allergens and viruses -- may point to treatments capable of slowing the spread of infectious respiratory diseases via sneezes," said Qin Liu, PhD, an associate professor of anesthesiology and the study's senior investigator.
The findings are published June 15 in the journal ...
Research led by the University of Kent and the STFC Rutherford Appleton Laboratory has resulted in the discovery of a new rare topological superconductor, LaPt3P. This discovery may be of huge importance to the future operations of quantum computers.
Superconductors are vital materials able to conduct electricity without any resistance when cooled below a certain temperature, making them highly desirable in a society needing to reduce its energy consumption.
Superconductors manifest quantum properties on the scale of everyday objects, making them highly attractive candidates for building computers which use quantum physics to store data ...
In the heart there are two different subtypes of beta-adrenergic receptors - beta1 and beta2 - which are activated by the stress hormones adrenaline and noradrenaline. They both trigger the strongest stimulation of the heart rate and pumping capacity that we know of. The two subtypes are highly similar biochemically, but differ substantially in terms of their functional and therapeutic relevance.
Both receptor types can stimulate the heart in the short term, yet when the beta1 receptor is activated over a prolonged period of time, it has a range ...
DUBLIN, June 15, 2021 - Scientists have identified how and why some Covid-19 patients can develop life-threatening clots, which could lead to targeted therapies that prevent this from happening.
The work, led by researchers from RCSI University of Medicine and Health Sciences, is published in the END ...
A new antibody testing study examining samples originally collected through the National Institutes of Health's All of Us Research Program found evidence of SARS-CoV-2 infections in five states earlier than had initially been reported. These findings were published in the journal Clinical Infectious Diseases. The results expand on findings from a Centers for Disease Control and Prevention study that suggested SARS-CoV-2, the virus that causes COVID-19, was present in the U.S. as far back as December 2019.
In the All of Us study, researchers analyzed more than 24,000 stored blood samples contributed ...
Chemotherapy kills tumour cells by causing damage to them. One of the most effective ways of causing damage is to prevent the two DNA strands from separating so that the cellular machinery cannot read the instructions written in the genes. But sometimes, the cell manages to repair the damage and survive, evading the effect of chemotherapy. CNIO researchers have found out how the cell does that and plan to use this knowledge to enhance cancer treatments.
The key lies in a peculiar protein called PrimPol, as explained in a publication in The EMBO Journal by the CNIO's DNA Replication Group, led by Juan Méndez.
The DNA molecule harbours the genes that direct the life of the cell and, ...
The University of Ottawa has been awarded four new Canada Research Chairs (CRC) that will strengthen its expertise in artificial intelligence, health and law. The University is also proud to announce the renewal of two CRCs that will conduct leading-edge research in quantum communications and photonics.
"The Canada Research Chairs Program provides invaluable support to our researchers as they forge their paths of discovery at a world-class level," said Sylvain Charbonneau, vice-president, research. "The results of this most recent competition will ...
A review of more than 9,000 U.S. patients with severe COVID-19 infection showed less than 1% contracted the illness again, with an average reinfection time of 3.5 months after an initial positive test. Those are the findings from a study conducted by researchers from the University of Missouri School of Medicine and MU Health Care.
The researchers teamed up with the MU Institute for Data Science and Informatics and the Tiger Institute for Health Innovation to review data from 62 U.S. health care facilities. They found 63 of the 9,119 patients (0.7%) with severe COVID-19 infection contracted the virus a second time, with a mean reinfection period of 116 days. Of the 63 who were reinfected, two (3.2%) died. Patients categorized as ...
Plants evolve specialised defence chemicals through the combined effects of genes, geography, demography and environmental conditions, a study published today in eLife reports.
The findings reveal a pattern in the types of defence chemicals plants produce across Europe, and describe some of the evolutionary processes that create them.
As plants are immobile organisms, they rely on producing defence chemicals called specialised metabolites for survival. Specialised metabolites have extensive variation in their structure, such as the number of carbon molecules ...
