Next Big Future April 24, 2018 A new mass-produced metamaterial developed by researchers in China is being tested on aircraft at a major military aircraft production base. Other countries, especially the United States, have also been heavily engaged in the research and development of similar technology to cloak military jets, but there have so far been no public reports on the mass application of such metamaterials overseas. Metamaterials were also extremely difficult to mass produce. Currently the technology was effective within only certain radio bandwidths… read more.
Energy conversion: Optical ‘overtones’ for solar cells
Science Daily April 19, 2018 In solar cells the spectral position of the window of light that can be efficiently converted is strongly related to its band-gap. Researchers in Germany measured the charge carrier density created by the absorption of multiple photons in perovskite nanocrystals. The efficiency of this process becomes drastically enhanced when the frequency of the primary light oscillation and frequency of the exciton at the band-gap become equal. The observation of this novel resonance phenomenon for optical excitations in excitonic semiconductors could pave the way for solar cells to more efficiently convert long-wavelength light into usable electric […]
Engineers develop technique to make adaptive materials
Science Daily April 17, 2018 A team of researchers in the US (ARL, University of Maryland) attached ultraviolet light reactive molecules to reinforcing agents, like carbon nanotubes, and embedded them in a polymer. When exposed to ultraviolet light, a chemical reaction occurs such that the interaction between the reinforcing agents and the polymer increases, making the material stiffer and stronger. In their experiment the materials became 93-percent stiffer and 35-percent stronger after a five-minute exposure to ultraviolet light. Applications include remote shaping of structural materials, adaptive soft robotics, and tunable intrinsic material damping… read more. TECHNICAL ARTICLE
For nuclear weapons reduction, a way to verify without revealing
Science Daily April 19, 2018 Researchers at MIT present a concept that leverages isotope-specific nuclear resonance phenomena to authenticate a warhead’s fissile components by comparing them to a previously authenticated template. All information is encrypted in the physical domain in a manner that amounts to a physical zero-knowledge proof system. Using Monte Carlo simulations, the system is shown to reveal no isotopic or geometric information about the weapon, while readily detecting hoaxing attempts. The method is a physical analog of data encryption. The team has verified the neutron concept through extensive simulations and now hopes to prove that it works […]
Far-red fluorescent silk can kill harmful bacteria as biomedical and environmental remedy
Nanowerk April 19, 2018 To combine the benefits of silk and green light, an international team of researchers (USA – Purdue University, South Korea) inserted the gene for “mKate2,” a far-red fluorescent protein, into a silk host. Shining a green light on the resulting hybrid generates reactive oxygen species (ROS), which are effective radicals for breaking down organic contaminants and attacking the membrane and DNA of pathogens. When E. coli on the fluorescent silk were illuminated by a weak green light for 60 minutes, the bacteria’s survival rate dropped to 45 percent. The hybrid could be processed into a solution, film, […]
Graphene sets a new record on squeezing light to one atom
Science Daily April 20, 2018 An international team of researchers (Spain, France, Portugal, USA – MIT) has shown that a graphene-insulator-metal heterostructure can overcome energy loss and demonstrate plasmon confinement down to the ultimate limit of the length scale of one atom. This is achieved through far-field excitation of plasmon modes squeezed into an atomically thin hexagonal boron nitride dielectric spacer between graphene and metal rods. A theoretical model that takes into account the nonlocal optical response of both graphene and metal is used to describe the results. These ultraconfined plasmonic modes, addressed with far-field light excitation, enable a route […]
Integrating optical components into existing chip designs
Nanowerk April 20, 2018 An international team of researchers (Belgium, USA – MIT, UC Berkeley, University of Colorado, Boston University, SUNY Albany, Switzerland) introduced photonics into bulk silicon CMOS chips using a layer of polycrystalline silicon deposited on silicon oxide islands fabricated alongside transistors. They implemented integrated high-speed optical transceivers in this platform that operate at ten gigabits per second, composed of millions of transistors, and arrayed on a single optical bus for wavelength division multiplexing. By decoupling the formation of photonic devices from that of transistors, this integration approach can achieve many of the goals of multi-chip solutions, but […]
Invisible magnetic sensors measure magnetic fields without disturbing them
Phys.org April 25, 2018 Researchers in Spain present a general strategy on how to make a sensor magnetically invisible while keeping its ability to sense. The sensor is rendered undetectable by surrounding it with a spherical shell having a tailored magnetic permeability. The method can be applied to arbitrary shape magnetic sensors in arbitrary magnetic fields. The invisibility can be made exact when the sensor is spherical, and the probed field is uniform. They are exploring cloaking properties for AC fields or incorporating the intriguing concept of negative static permeability for creating novel shapes of magnetic fields… read more. Open […]
New thermal coatings for spacecraft and satellites developed using metamaterials
Phys.org April 25, 2018 Optical solar reflectors (OSRs) made of quartz tiles designed to reject solar radiation and dissipate the heat that is generated on board satellites, are heavy, fragile, cannot be applied to curved surfaces and add significantly to assembly and launch costs. An international team of researchers (UK, Italy, Denmark) working on Horizon 2020 sponsored space technology project, developed a new meta-OSR coating enabled by the use of metal oxide that has very strong infrared emissivity while retaining a low absorption of the solar spectrum. A ‘smart’ radiator based on their metamaterial design allows tuning of the radiative […]
Playing quantum catch in new research
Science Daily April 23, 2018 For a quantum computer to run more complex algorithms, qubits must be interfaced with each other. Researchers at Yale University ‘pitched’ a qubit from one physical point in a microwave cavity to a separate point in a different cavity while it preserved and caught the information. They carefully shape their pitch-and-catch over time, so that both ends of the transaction are in sync. Pitch and catch also includes quantum entanglement. In this instance, it means the pitcher is pitching and not pitching, simultaneously. Remote entanglement will be crucial in quantum networks… read more. Open Access […]