Phys.org October 20, 2020 Going beyond an improved colour gamut, an asymmetric colour contrast, which depends on the viewing direction, and its ability to readily deliver information could create opportunities for a wide range of applications, such as next-generation optical switches, colour displays, and security features in anti-counterfeiting devices. Researchers in South Korea propose a simple Fabry–Perot etalon architecture capable of generating viewing-direction-sensitive colour contrasts and encrypting pre-inscribed information upon immersion in particular solvents. Based on the experimental verification of the theoretical modelling, they have discovered a completely new and exotic optical phenomenon involving a tunable colour switch for viewing-direction-dependent […]
The chips of the future will include programmable photonic circuits
Nanowerk October 19, 2020 The increase in complexity of circuits has introduced a generation of photonic circuits that can be programmed using software for a wide variety of functions through a mesh of on-chip waveguides, tunable beam couplers and optical phase shifters. An international team of researchers (Belgium, Spain, USA – Stanford University, MIT, Germany, Canada, Italy) discusses the state of this emerging technology, including recent developments in photonic building blocks and circuit architectures, as well as electronic control and programming strategies. They cover possible applications in linear matrix operations, quantum information processing and microwave photonics, and examine how these […]
‘Classified knots’: Researchers create optical framed knots to encode information
Phys.org October 17, 2020 Modern beam shaping techniques have enabled the generation of optical fields displaying a wealth of structural features. Due to their robustness against external perturbations, topological invariants in physical systems are increasingly being considered to encode information. Hence, structured light with topological properties could potentially be used for such purposes. An international team of researchers (Canada, USA – MIT, Israel) has experimentally demonstrated structures known as framed knots within optical polarization fields. They developed a protocol in which the topological properties of framed knots are used in conjunction with prime factorization to encode information…read more. Open Access […]
A controllable membrane to pull carbon dioxide out of exhaust streams
MIT News October 16, 2020 Researchers at MIT have developed a gas gating mechanism driven by reversible electrochemical metal deposition/dissolution on a conductive membrane, which can continuously modulate the interfacial gas permeability over two orders of magnitude with high efficiency and short response time. The gating mechanism involves neither moving parts nor dead volume and can therefore enable various engineering processes. An electrochemically mediated carbon dioxide concentrator demonstrates proof of concept by integrating the gating membranes with redox-active sorbents, where gating effectively prevented the crosstalk between feed and product gas streams for high-efficiency, directional carbon dioxide pumping. The system could […]
Eight Lincoln Laboratory technologies named 2020 R&D 100 Award winners
MIT News October 20, 2020 Eight technologies developed by MIT Lincoln Laboratory researchers, either wholly or in collaboration with researchers from other organizations, were among the winners of the 2020 R&D 100 Awards. Six of the laboratory’s winning technologies are software systems, several of them take advantage of artificial intelligence techniques. The software technologies are solutions to difficulties inherent in analyzing large volumes of data and to problems in maintaining cybersecurity. Another technology is a process designed to assure secure fabrication of integrated circuits, and the eighth winner is an optical communications technology that may enable future space missions to […]
A flexible color-changing film inspired by chameleon skin (w/video)
Nanowerk October 21, 2020 By tensing or relaxing their skin, chameleons can change the way light reflects from guanine crystals under the surface, producing structural coloration. The structural colors are different from the pigments that give many other creatures their hues. Currently available materials for mimicking chameleon skin is difficult to produce. Researchers in China introduced a flexible network structure in cellulose nanocrystals (CNCs), exerting a bridge effect for the rigid nanomaterials. These films display high flexibility with a fracture strain of up to 39%. Notably, stretching-induced structural color changes visible to the naked eye are realized, for the first […]
Good vibrations for new energy
Nanowerk October 20, 2020 Triboelectric nanogenerators (TENGs) can be made at low cost in different configurations, making them suitable for driving small electronics such as mobile phones, biomechanics devices, and sensors. Researchers in Australia provide experimental and theoretical models for augmented rotary TENGs. The power generated by TENGs is found to be a function of the number of segments, rotational speed, and tribo-surface spacing. They applied mathematical modeling combined with artificial intelligence to characterize the TENG output under various kinematics and geometric conditions. Sensitivity analysis reveals that the generated energy and the matched resistance depend highly on segmentation and angular […]
Integrated circuit of pure magnons
Nanowerk October 20, 2020 Magnons have been used to encode information in computing applications, and magnonic device components, including logic gates, transistors, and units for non-Boolean computing. Magnonic directional couplers, which can function as circuit building blocks have been impractical because of their millimetre dimensions and multimode spectra. An international team of researchers (Austria, Ukraine, Germany, Belgium, the Netherlands) has developed a magnonic directional coupler based on yttrium iron garnet that has submicrometre dimensions. The coupler consists of single-mode waveguides with a width of 350 nm. They used the amplitude of a spin wave to encode information and to guide it […]
Materials scientists discover design secrets of nearly indestructible insect
Nanowerk October 21, 2020 The ironclad beetle is one formidable insect which has an exoskeleton that is one of the toughest, most crush-resistant structures known to exist in the biological world. An international team of researchers (USA – UC Riverside, Purdue University, UT San Antonio, Lawrence Berkeley National Laboratory, UC Irvine, Japan) used advanced microscopy, spectroscopy and in situ mechanical testing, and identified multiscale architectural designs within the exoskeleton of the beetle, and examined the resulting mechanical response and toughening mechanisms. They highlighted a series of interdigitated sutures, the ellipsoidal geometry and laminated microstructure which provide mechanical interlocking and toughening […]
Optical wiring for large quantum computers
Phy.org October 22, 2020 The fundamental qualities of individual trapped-ion qubits are promising for long-term systems, but the optics involved in their precise control are a barrier to scaling. Researchers in Switzerland used scalable optics co-fabricated with a surface-electrode ion trap to achieve high-fidelity multi-ion quantum logic gates, which are often the limiting elements in building up the precise, large-scale entanglement that is essential to quantum computation. Light is efficiently delivered to a trap chip in a cryogenic environment via direct fibre coupling on multiple channels, eliminating the need for beam alignment into vacuum systems and cryostats and lending robustness […]