Phys.org April 1, 2020 Researchers in China freeze-spun silk and chitosan, a material from the hard outer skeleton of shellfish, into colored fibers with porous microstructures. They filled the pores with polyethylene glycol (PEG), a phase-changing polymer that absorbs and releases thermal energy. The threads were coated with polydimethylsiloxane to keep the liquid PEG from leaking out. The resulting fibers were strong, flexible, and water-repellent. To test the fibers, the researchers wove them into a patch of fabric and put inside a polyester glove. When a person wearing the glove placed their hand in a hot chamber (122°F), the solid […]
Novel tin ‘bubbles’ spur advances in the development of integrated chips
EurekAlert April 15, 2020 Low density materials can control plasma properties of laser absorption, which can enhance quantum beam generation. Researchers in Japan propose a target source based on a hollow sub-millimeter microcapsule fabricated from polyelectrolyte cationic and anionic surfactant on air bubbles. The lightweight microcapsules acted as a scaffold for surface coating by tin (IV) oxide nanoparticles. In a proof of concept study the laser conversion efficiency at 13.5 nm 2% bandwidth from the tin-coated microcapsule (0.8%) was competitive compared with bulk tin (1%). According to the researchers microcapsule aggregates could be utilized as a potential small scale/compact EUV source […]
Penn Engineering’s New Scavenger Technology Allows Robots to ‘Eat’ Metal for Energy
University of Pennsylvania, April 6, 2020 The metal-air scavenger developed by researchers at the University of Pennsylvania works like a battery by providing power by repeatedly breaking and forming a series of chemical bonds and a harvester as the power is supplied by energy in the chemical bonds in metal and air surrounding the metal-air scavenger. They showed that a range of hydrogel electrolyte compositions can be combined with air cathodes to extract 159, 87, and 179 mAh/cm2 capacities from aluminum, zinc, and steel surfaces at up to 130, 81, and 25 mW/cm2 power densities, which exceed the power density […]
A perovskite-based diode capable of both light emission and detection
Phys.org April 10, 2020 An international team of researchers (Sweden, China, Italy, Switzerland) has developed an efficient solution-processed perovskite diode that can work in both emission and detection modes. The device can be switched between modes by changing the bias direction, and it exhibits light emission with an external quantum efficiency of over 21% and a light detection limit on a subpicowatt scale. The operation speed for both functions can reach tens of megahertz. The diodes exhibit a high specific detectivity at its peak emission (~804 nm), which allows an optical signal exchange between two identical diodes. To illustrate the potential […]
Quickly-grown graphite film blocks electromagnetic radiation
Physics World April 11, 2020 Techniques for manufacturing graphite films take several hours and require processing temperatures of around 3000°C. Researchers in China produced high-quality graphite film tens of nanometres thick within a few seconds by heating nickel foil to 1200°C in an argon atmosphere and then rapidly immersing this foil in ethanol at 0°C. The carbon atoms produced from the decomposition of ethanol diffuse and dissolve into the nickel because of its high carbon solubility. As this carbon solubility greatly decreases at low temperature, the carbon atoms subsequently segregate and precipitate from the nickel surface during quenching, producing a […]
Simple method for ceramic-based flexible electrolyte sheets for lithium metal batteries
EurekAlert April 11, 2020 The garnet-type ceramic Li7La3Zr2O12 (LLZO) is one of the few solid-state fast-ion conductors that is stable against Li metal. However, the densification of LLZO powders usually requires high sintering temperatures which likely results in Li loss and various side reactions. Researchers in Japan have developed a process to make flexible composite Al-doped LLZO (Al-LLZO) sheet electrolyte which can be mass-produced at room temperature. The sheet electrolyte enables Li-metal batteries to operate at both 60 and 30 °C, demonstrating its potential application for developing practical Li-metal batteries…read more. TECHNICAL ARTICLE
Trapped ytterbium ions could form backbone of a quantum internet, say researchers
Phys.org April 13, 2020 An international team of researchers (USA – University of Colorado, NIST, Caltech, Australia, Singapore) fabricated a periodic, nano-patterned 10 micron-long cavity with the ion at its centre. Light bounces back and forth many times in the cavity, greatly increasing the chance of the light interacting with the ion. The researchers then manipulated their ion qubit using laser and microwave pulses. The result is the emission of a photon that is entangled with the qubit – a photon that itself is a flying qubit of quantum information. More than 99% of the time, they found that this […]
Untwisting plastics for charging internet-of-things devices
Science Daily April 16, 2020 To use body heat to charge some types of micro-devices and sensors lightweight, non-toxic, wearable, and flexible thermoelectric generators are required. Japan studied the thermoelectric properties of highly conductive thiophene-based polymer, called PBTTT. They doped the polymer with a thin ion electrolyte gel, which is known to improve conductivity that infiltrates the polymer successfully when a specific electric voltage is applied. They found that, without the electrolyte gel, the PBTTT chain is highly twisted. Doping it with a critical amount of electrolyte untwists the chain and creates links between its crystalline parts, improving electron conductivity. […]
World’s most complex microparticle: A synthetic that outdoes nature’s intricacy
Nanowerk April 10, 2020 The structural complexity of composite biomaterials and biomineralized particles arises from the hierarchical ordering of inorganic building blocks over multiple scales. An international team of researchers (USA – University of Michigan, Caltech, University of Pennsylvania, Brazil) assembled hierarchically organized particles (HOPs) with twisted spikes and other morphologies from polydisperse Au-Cyc nanoplatelets. Its complexity is higher than biological counterparts or other complex particles. Their intricate organization emerges from competing chirality-dependent assembly restrictions that render assembly pathways primarily dependent on nanoparticle symmetry rather than size. The researchers believe that the tactics they have uncovered can help scientists engineer […]
Top 10 Science and Technology Inventions for the Week of April 10, 2020
01. Researchers develop one-way street for electrons 02. Broad spectrum: Novel hybrid material proves an efficient photodetector 03. Innovative technologies for satellites 04. Squeezing Light Out of Silicon 05. Magnetoacoustic waves: Towards a new paradigm of on-chip communication 06. Researchers demonstrate a platform for future optical transistors 07. A twist connecting magnetism and electronic-band topology 08. Team develops foldable and washable luminescent film 09. Sliding walls – a new paradigm for microfluidic devices 10. Engineers use metal-oxide nanomaterials deposited on cloth to wipe out microbes And others… ‘Amazing’ Math Bridge Extended Beyond Fermat’s Last Theorem Black hole bends light back […]