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Archive for the ‘materials’ category: Page 217

Sep 12, 2019

Engineers develop ‘blackest black’ material to date

Posted by in categories: materials, nanotechnology

With apologies to “Spinal Tap,” it appears that black can, indeed, get more black.

MIT engineers report today that they have cooked up a material that is 10 times blacker than anything that has previously been reported. The material is made from vertically aligned nanotubes, or CNTs—microscopic filaments of carbon, like a fuzzy forest of tiny trees, that the team grew on a surface of chlorine-etched . The foil captures more than 99.96 percent of any incoming light, making it the blackest material on record.

The researchers have published their findings today in the journal ACS-Applied Materials and Interfaces. They are also showcasing the cloak-like material as part of a new exhibit today at the New York Stock Exchange, titled “The Redemption of Vanity.”

Sep 12, 2019

Researchers produce synthetic Hall Effect to achieve one-way radio transmission

Posted by in categories: materials, particle physics

Researchers at the University of Illinois at Urbana-Champaign have replicated one of the most well-known electromagnetic effects in physics, the Hall Effect, using radio waves (photons) instead of electric current (electrons). Their technique could be used to create advanced communication systems that boost signal transmission in one direction while simultaneously absorbing signals going in the opposite direction.

The Hall Effect, discovered in 1879 by Edwin Hall, occurs because of the interaction between charged particles and . In an electric field, negatively charged particles (electrons) experience a force opposite to the direction of the field. In a , moving electrons experience a force in the direction perpendicular to both their motion and the magnetic field. These two forces combine in the Hall Effect, where perpendicular electric and magnetic fields combine to generate an . Light isn’t charged, so regular electric and magnetic fields can’t be used to generate an analogous “current of light.” However, in a recent paper published in Physical Review Letters, researchers have done exactly this with the help of what they call “synthetic electric and magnetic fields.”

Principal investigator Gaurav Bahl’s research group has been working on several methods to improve radio and optical data transmission as well as fiber optic communication. Earlier this year, the group exploited an interaction between light and sound waves to suppress the scattering of light from material defects and published its results in Optica. In 2018, team member Christopher Peterson was the lead author in a Science Advances paper which explained a technology that promises to halve the bandwidth needed for communications by allowing an antenna to send and receive signals on the same frequency simultaneously through a process called nonreciprocal coupling.

Sep 11, 2019

Love The Netherlands

Posted by in categories: materials, transportation

The Netherlands is building roads out of plastic waste. Take a journey down the plastic highway 😍😍.


The Netherlands is building roads out of plastic waste. Take a journey down the plastic highway 😍 😍

🎥 : World Economic Forum #lovethenetherlands #1sttheworld

Sep 11, 2019

Finally, scientists have designed a material that repairs damaged tooth enamel by precisely reproducing its complex, fish scale-like structure and mechanical properties

Posted by in category: materials

Sep 10, 2019

Stretchy plastic electrolytes could enable new lithium-ion battery design

Posted by in category: materials

The growing popularity of lithium-ion batteries in recent years has put a strain on the world’s supply of cobalt and nickel—two metals integral to current battery designs—and sent prices surging.

In a bid to develop alternative designs for lithium-based batteries with less reliance on those , researchers at the Georgia Institute of Technology have developed a promising new and system that replaces expensive metals and traditional liquid electrolyte with lower cost transition metal fluorides and a .

“Electrodes made from transition metal fluorides have long shown stability problems and rapid failure, leading to significant skepticism about their ability to be used in next generation batteries,” said Gleb Yushin, a professor in Georgia Tech’s School of Materials Science and Engineering. “But we’ve shown that when used with a solid polymer electrolyte, the metal fluorides show remarkable stability—even at —which could eventually lead to safer, lighter and cheaper lithium-ion batteries.”

Sep 10, 2019

A soft phototactic swimming robot built using a self-sustained hydrogel oscillator

Posted by in categories: materials, robotics/AI

Researchers at the University of California, Los Angeles (UCLA) and the California NanoSystems Institute in Los Angeles have recently developed a soft swimming robot based on a self-sustained hydrogel oscillator. This robot, presented in a paper published in Science Robotics, operates under constant light input without the need for a battery.

“When I shone on a soft, fast responsive hydrogel pillar, I observed the pillar started to oscillate around the optical beam,” Yusen Zhao, a Ph.D. student involved in the research, said. “It looked very intriguing to me, and I wondered: How can a constant input produce intermittent output? Under what conditions does the oscillation happen? Would it be powerful enough to propel and swim in water, and eventually lead to solar sails? With these questions, I continued systematic studies aiming to achieve these objectives.”

Zhao and his colleagues developed a soft oscillator made of a light-responsive soft gel, which is molded into the shape of a pillar or strip. When light hits a spot of this gel pillar, it is automatically absorbed and converted into heat. The locally heated spot on the causes it to eject some of its water and shrink in volume, resulting in its tail bending towards the light source.

Sep 9, 2019

Hard as a diamond? Scientists predict new forms of superhard carbon

Posted by in categories: materials, particle physics

Superhard materials can slice, drill and polish other objects. They also hold potential for creating scratch-resistant coatings that could help keep expensive equipment safe from damage.

Now, science is opening the door to the development of new materials with these seductive qualities.

Researchers have used computational techniques to identify 43 previously unknown forms of that are thought to be stable and superhard—including several predicted to be slightly harder than or nearly as hard as diamonds. Each new carbon variety consists of carbon atoms arranged in a distinct pattern in a .

Sep 9, 2019

Crucial New Aspect of Charge Density Modulations in High Temperature Superconductors Uncovered

Posted by in category: materials

Researchers from Chalmers University of Technology and Politecnico di Milano have identified a crucial new aspect of charge density modulations in cuprate high critical temperature superconductors. They have identified a new electron wave which could help reveal some of the mysteries about superconducting materials. The findings are published in the journal Science.

High critical temperature superconductors have a variable charge density, meaning that their electrical charge is unevenly distributed. This partly results from what are known as ‘charge density waves’, which were discovered a few years ago. But these have only been observed to exist sporadically, under certain conditions. Therefore, they were not believed to be a contributing factor to the materials’ superconducting properties.

What the researchers have now discovered, however, is an additional aspect to the variable charge density, which they term “charge density fluctuations”. These have been identified as an additional charge modulation, collective and with a shorter correlation length. They are very pervasive, meaning that compared to the conventional charge density waves, they are present at a much greater range of temperatures, up to room temperature and beyond, and at different levels of oxygen doping.

Sep 6, 2019

Measuring changes in magnetic order to find ways to transcend conventional electronics

Posted by in categories: futurism, materials

Researchers around the world are constantly looking for ways to enhance or transcend the capabilities of electronic devices, which seem to be reaching their theoretical limits. Undoubtedly, one of the most important advantages of electronic technology is its speed, which, albeit high, can still be surpassed by orders of magnitude through other approaches that are not yet commercially available.

A possible way of surpassing traditional electronics is through the use of (AFM) materials. The electrons of AFM materials spontaneously align themselves in such a way that the overall magnetization of the material is practically zero. In fact, the order of an AFM material can be quantified in what is known as the ‘order parameter.’ Recent studies have even shown that the AFM order parameter can be ‘switched’ (that is, changed from one known value to another, really fast) using light or , which means that AFM materials could become the building blocks of future electronic devices.

However, the dynamics of the order-switching process are not understood because it is very difficult to measure the changes in the AFM order parameter in real time with high resolution. Current approaches rely on measuring only certain phenomena during AFM order switching and trying to obtain the full picture from there, which has proven to be unreliable for understanding other more intricate phenomena in detail. Therefore, a research team lead by Prof. Takuya Satoh from Tokyo Tech and researchers from ETH Zurich, developed a method for thoroughly measuring the changes in the AFM order of an YMnO3 crystal induced through optical excitation (that is, using a laser).

Aug 30, 2019

A predicted superconductor might work at a record-breaking 200° Celsius

Posted by in category: materials

Y. Sun et al. Route to a superconducting phase above room temperature in electron-doped hydride compounds under high pressure. Physical Review Letters. Vol. 123, August 30, 2019. doi:10.1103/PhysRevLett.123.097001.