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Archive for the ‘materials’ category: Page 190

Nov 12, 2020

G-wave superconductor comes into view

Posted by in category: materials

Researchers discover an unexpected new class of superconducting material.


Superconducting materials are traditionally classed into two types: s-wave and d-wave. A third type, p-wave, has long been predicted. Now, however, researchers in the US, Germany and Japan say they may have discovered a fourth, unexpected type of superconductor: g-wave. The result, obtained thanks to high-precision resonant ultrasound spectroscopy measurements on strontium ruthenate, could shed fresh light on the Cooper pairing mechanisms in so-called unconventional superconductors.

Nov 11, 2020

New 3D printing technique fuses titanium particles at supersonic speeds

Posted by in categories: biotech/medical, materials

Engineers at Cornell University have developed a new technique for 3D printing metallic objects – and it involves blasting titanium particles at supersonic speeds. The resulting metals are very porous, which makes them particularly useful for biomedical objects like implants and replacement joints.

Traditional 3D printing involves a nozzle depositing plastic, hydrogels, living cells or other materials layer by layer to build up an object. Metal parts and objects are usually 3D printed in other ways, such as firing a laser at a bed of metal powder to selectively melt sections into the desired shape, or firing metal powder at high speeds at a substrate to fuse the particles together.

The latter method is known as “cold spray,” and the new technique expands on that base. The Cornell team blasted titanium alloy particles, each measuring between 45 and 106 microns wide, at speeds up to 600 m (1,969 ft) per second (for reference, the speed of sound in air is around 340 m (1,115 ft) per second). The team calculated this as the ideal speed – any faster, and the particles would disintegrate too much on impact to bond to each other.

Nov 9, 2020

Researchers decode thermal conductivity with light

Posted by in categories: materials, nanotechnology

Groundbreaking science is often the result of true collaboration, with researchers in a variety of fields, viewpoints and experiences coming together in a unique way. One such effort by Clemson University researchers has led to a discovery that could change the way the science of thermoelectrics moves forward.

Graduate research assistant Prakash Parajuli; research assistant professor Sriparna Bhattacharya; and Clemson Nanomaterials Institute (CNI) Founding Director Apparao Rao (all members of CNI in the College of Science’s Department of Physics and Astronomy) worked with an international team of scientists to examine a highly efficient thermoelectric material in a new way—by using light.

Their research has been published in the journal Advanced Science and is titled “High zT and its origin in Sb-doped GeTe single crystals.”

Nov 9, 2020

UK firm to turn moon rock into oxygen and building materials

Posted by in categories: materials, space travel

“Anything you take from Earth to the moon is an added weight that you don’t want to carry, so if you can make these materials in situ it saves you a lot of time, effort and money,” said Ian Mellor, the managing director of Metalysis, which is based in Sheffield.

Analyses of rocks brought back from the moon reveal that oxygen makes up about 45% of the material by weight. The remainder is largely iron, aluminium and silicon. In work published this year, scientists at Metalysis and the University of Glasgow found they could extract 96% of the oxygen from simulated lunar soil, leaving useful metal alloy powders behind.

NASA and other space agencies are in advanced preparations to return to the moon, this time to establish a permanent lunar base, or “moon village” where nations will operate alongside private companies on critical technologies such as life support, habitat construction, energy generation and food and materials production.

Nov 8, 2020

Researchers claim their graphene “SuperBattery” achieves a 15-second charging time

Posted by in categories: energy, materials

Skeleton Technologies and the Karlsruhe Institute of Technology (KIT) say they have developed a graphene-based battery with a 15-second charging time, as well as charging cycles counted in the hundreds of thousands.

The so-called SuperBattery’s key component is Skeleton’s patented Curved Graphene carbon material, which enables the high power and long lifetime of ultracapacitors to be applied in a graphene battery.

“The SuperBattery is a game-changer for the automotive industry. Together with Li-ion batteries, they have it all: high energy and power density, long lifetime and 15-second charging time,” said Skeleton Technologies CEO Taavi Madiberk.

Nov 7, 2020

Pushing the envelope with fusion magnets

Posted by in categories: energy, materials

David Fischer, an MIT Energy Fellow at the Plasma Science and Fusion Center, is observing ways irradiation damages thin high-temperature superconductor tapes in the design of ARC, a fusion pilot plant concept.

Nov 7, 2020

New Kind of Superconductivity Discovered: Researchers Demonstrate a Superconductor Previously Thought Impossible

Posted by in categories: biotech/medical, materials

Superconductivity is a phenomenon where an electric circuit loses its resistance and becomes extremely efficient under certain conditions. There are different ways in which this can happen which were thought to be incompatible. For the first time, researchers discover a bridge between two of these methods to achieve superconductivity. This new knowledge could lead to a more general understanding of the phenomena, and one day to applications.

If you’re like most people, there are three states of matter in your everyday life: solid, liquid, and gas. You might be familiar with a fourth state of matter called plasma, which is like a gas that got so hot all its constituent atoms came apart, leaving behind a super hot mess of subatomic particles. But did you know about a so-called fifth state of matter at the complete opposite end of the thermometer? It’s known as a Bose-Einstein condensate (BEC).

“A BEC is a unique state of matter as it is not made from particles, but rather waves,” said Associate Professor Kozo Okazaki from the Institute for Solid State Physics at the University of Tokyo. “As they cool down to near absolute zero, the atoms of certain materials become smeared out over space. This smearing increases until the atoms — now more like waves than particles — overlap, becoming indistinguishable from one another. The resulting matter behaves like it’s one single entity with new properties the preceding solid, liquid or gas states lacked, such as superconduction. Until recently superconducting BECs were purely theoretical, but we have now demonstrated this in the lab with a novel material based on iron and selenium (a nonmetallic element).”

Nov 7, 2020

DefeXtiles: 3D printing quasi-woven textiles via underextrusion

Posted by in category: materials

OverviewDefeXtiles are thin, flexible textiles of many materials that can quickly be printed into a variety of 3D forms using an inexpensive, unmodified, 3D printer with no additional software.

Nov 5, 2020

Moiré lattices used to induce formation of optical solitons

Posted by in categories: materials, particle physics

A team of researchers from China, Spain, Russia and Portugal has developed a way to use Moiré lattices to optically induce and highlight the formation of optical solitons under different geometrical conditions. In their paper published in the journal Nature Photonics, the group describes their work, which involved using photorefractive nonlinear media as a means of localizing laser light into tight spots.

Solitons are quasiparticles propagated by a traveling wave. Unlike waves such as those produced in water, solitons are neither followed nor preceded by other such waves—they also hold their shape as they move. They are important because they are able to prevent diffraction from occurring, which is why they play such an important role in telecommunications and other information carrier systems. Moiré lattices are patterns that sometimes emerge in printed or scanned images when two patterns overlap one another in an offset fashion. They have been used in graphene-based research efforts and work that involves manipulating very cold atoms. They have also been found to play a roll in the development of colloidal clusters.

In this new work, the researchers were investigating the ways that light could be stopped from spreading—more specifically, ways that laser light could be trapped in a tight spot. To that end, they used a laser beam to stencil a special a type of crystal: a photorefractive strontium barium niobite crystal with nonlinear holographic properties. The stencil forced a beam of laser light to form into a twisted Moiré lattice. As the light moved through the lattice, the researchers found that solitons formed. They also found that they could adjust the threshold of the laser power by fine-tuning the angles of the twists in the lattice. Additionally, the formation of solitons in the lattices occurred with smooth transitions, from fully periodic geometries to aperiodic ones. The researchers also noted that such thresholds in their setup were quite low.

Nov 2, 2020

Nylon finally takes its place as a piezoelectric textile

Posted by in categories: energy, materials

Nylon might seem the obvious go-to material for electronic textiles—not only is there an established textiles industry based on nylon, but it conveniently has a crystalline phase that is piezoelectric—tap it and you get a build-up of charge perfect for pressure sensing and harvesting energy from ambient motion.

Unfortunately, forming into fibers while getting it to take on the crystal structure that has a is not straightforward. “This has been a challenge for almost half a century,” explains Kamal Asadi, a researcher at the Max-Planck Institute for Polymer Research, Germany, and professor at the University of Bath, U.K. In a recent Advanced Functional Materials report, he and his collaborators describe how they have now finally overcome this.

The piezoelectric phase of nylon holds appeal not just for electronic textiles but all kinds of electronic devices, particularly where there is demand for something less brittle than the conventional piezoelectric ceramics. However, for decades, the only way to produce nylon with the crystalline phase that has a strong piezoelectric response has been to melt it, rapidly cool it and then stretch it so that it sets into a smectic δ’ phase. This produces slabs typically tens of micrometers thick—far too thick for applications in electronic devices or electronic textiles.