A collaboration of researchers has discovered that sodium bismuthate can exist as a form of quantum matter called a 3-D topological Dirac semi-metal (3DTDS). This is the first experimental confirmation of 3-D Dirac fermions in the interior or bulk of a material, a novel state that was only recently proposed by theorists. It is a natural counterpart because of its magnetoresistive properties.
Researchers at the Univ. of Delaware have developed a “smart” hydrogel that can deliver medicine on demand, in response to mechanical force. Over the past few decades, smart hydrogels have been created that respond to pH, temperature, DNA, light and other stimuli.
Using an approach akin to assembling a club sandwich at the nanoscale, NIST researchers have succeeded in crafting a uniform, multi-walled carbon nanotube-based coating that greatly reduces the flammability of foam commonly used in upholstered furniture and other soft furnishings. The flammability of the nanotube-coated polyurethane foam was reduced 35% compared with untreated foam.
“The interface is the device,” Nobel laureate Herbert Kroemer famously observed, referring to the remarkable properties to be found at the junctures where layers of different materials meet. In today’s burgeoning world of nanotechnology, the interfaces between layers of metal oxides are becoming increasingly prominent. Realizing the vast potential of these metal oxide interfaces requires detailed knowledge of their electronic structure.
For decades, increasing amounts of data have been successfully stored on media with ever-higher densities. Now, an international team has discovered a physical phenomenon that could prove suitable for use in further data aggregation. Researchers found that domain walls, which separate areas in certain crystalline materials, display a polarization, potentially allowing information to be stored in the tiniest of spaces.
A team at the Laboratory for Attosecond Physics in Germany has constructed a detector which provides a detailed picture of the waveforms of femtosecond laser pulses. Knowledge of the exact waveform of these pulses enables scientists to reproducibly generate light flashes that are a thousand times shorter, just attoseconds, and can be used to study ultrafast processes at the molecular and atomic levels.
A new development by researchers at the Univ. of California, Berkeley, could lead to curtains and other materials that move in response to light, no batteries needed. Engineers have created a new light-reactive material made up of carbon nanotubes and plastic polycarbonate.
A new fabrication method inspired by blown sugar art has been used to make structure in which an ultrathin graphene layer, or layers, is glued to a 3-D strutted framework. The researchers in Japan, calling this the “chemical blowing method”, overcomes the weak intersheet connections that have made this type of structure so difficult to create in the past.
The field of metamaterials has produced structures with unprecedented abilities, including flat lenses, invisibility cloaks and even optical metatronic devices that can manipulate light in the way electronic circuitry manipulates the flow of electrons. Now, the birthplace of the digital computer, ENIAC, is using this technology in the rebirth of analog computing.
It's known that electric vehicles could travel longer distances before needing to charge and more renewable energy could be saved for a rainy day if lithium-sulfur batteries can just overcome a few technical hurdles. Now, a novel design for a critical part of the battery has been shown to significantly extend the technology's lifespan, bringing it closer to commercial use.
Researchers at Oak Ridge National Laboratory and the Univ. of Tennessee, Knoxville have pioneered a new technique for forming a 2-D, single-atom sheet of two different materials with a seamless boundary. The study could enable the use of new types of 2-D hybrid materials in technological applications and fundamental research.
Lithium batteries, with their exceptional ability to store power per a given weight, have been a major focus of research to enable use in everything from portable electronics to electric cars. Now researchers at Massachusetts Institute of Technology and Brookhaven National Laboratory have found a whole new avenue for such research: the use of disordered materials, which had generally been considered unsuitable for batteries.
To understand how to design better thermoelectric materials, researchers are using neutron scattering at the Spallation Neutron Source and the High Flux Isotope Reactor at Oak Ridge National Laboratory to study how silver antimony telluride is able to effectively prevent heat from propagating through it on the microscopic level.
By replacing platinum with molybdenum in photoelectrochemical cells, scientists from two Swiss labs have developed a cheaper and scalable technique that can greatly improve hydrogen production through water splitting as a means of storing solar energy.
A research group at Japan’s National Institute for Materials Science has developed a method for creating a bandgap in graphene oxide by changing the bonding state of carbon atoms that compose graphene through reversible absorption and desorption of oxygen atoms on the graphene. This allows in situ bandgap tuning, which could help develop high-performance nanoscale devices using graphene oxide membranes.
The sensors team at the National Energy Technology Laboratory is working on sensor technologies to enable embedded gas sensing at high temperature. Through a combination of theoretical simulations and experiments, the team has demonstrated that transparent conducting oxides such as aluminum-doped zinc oxide show significant promise for high-temperature optical gas sensing in the near‑infrared wavelength range.
A spin-off company from Singapore’s A*STAR research institute, has invented a new plastic film using a nano-inspired process that makes the material thinner but as effective as aluminium foil in keeping air and moisture at bay. The stretchable plastic could be an alternative for prolonging shelf-life of pharmaceuticals, food, and electronics, bridging the gap of aluminium foil and transparent oxide films.
In the search for cheaper materials that mimic their purer, more expensive counterparts, researchers are abandoning hunches and intuition for theoretical models and pure computing power. In a new study, researchers from Duke Univ.’s Pratt School of Engineering used computational methods to identify dozens of platinum-group alloys that were previously unknown to science but could prove beneficial in a wide range of applications.
To manufacture plastic parts with high-end surfaces, the entire forming tool is heated to 110 C using a technique known as variothermic tempering. To retrieve the finished plastic part, the mold must be cooled by up to 30 C, consuming lots of energy. Researchers have now developed a new kind of tempering technique that is up to 90% more energy efficient than variothermic tempering approaches.
Inspired by how beetles and tree frogs keep their feet attached to submerged leaves, researchers in Singapore have revealed a new method that allows both the growth and transfer steps of graphene on a silicon wafer. This technique enables the graphene to be applied in photonics and electronics, for devices such as optoelectronic modulators, transistors, on-chip biosensors, and tunnelling barriers.
A research group based in Japan has succeeded for the first time in fabricating a 3-D structure of a quasicrystal composed of a single element. Discovered in 1984, quasicrystals have been found in more than 100 kinds of alloy, polymer and nanoparticle systems. However, a quasicrystal composed of a single element has not yet been found.
In two complementary studies, an international team of physicists has now established that superconductivity in high-temperature superconductors, known as cuprates, collapses at a maximum of -135 C due to the formation of charge-density waves. Consequently, in order to find superconductors that drop to zero resistance at realistic temperatures, materials scientists must search for substances that are not subject to charge-density waves.
According to new research at the Massachusetts Institute of Technology, graphene, under an extremely powerful magnetic field and at extremely low temperature, can effectively filter electrons according to the direction of their spin. This is something that cannot be done by any conventional electronic system and could render graphene suitable for exotic uses such as quantum computing.
In earlier studies, a team from the Univ. of Pennsylvania produced nanoscale grids and rings of “defects,” or useful disruptions in the repeating patterns found in liquid crystals. Their latest study adds a more complex pattern out of an even simpler template: A 3-D array in the shape of a flower. This advances the use of liquid crystals as a medium for assembling structures.
A team of researchers with Lawrence Berkeley National Laboratory has demonstrated a micro-sized robotic torsional muscle/motor made from vanadium dioxide that for its size is a thousand times more powerful than a human muscle. It is able to catapult objects 50 times heavier than itself over a distance five times its length within just 60 milliseconds.