Lifeboat Foundation

No matter how good a material is at conducting electricity, there’s usually some resistance – unless you use superconductive materials. Since they can conduct electricity with absolutely no loss, they could be revolutionary if not for one little problem: they only work if kept extremely cold. But now researchers at Max Planck have reported a new record high temperature for superconductivity, at a toasty −23° C (−9.4° F).

Space vehicles like SpaceX’s Falcon 9 are designed to be reusable. But this means that, like Olympic gymnasts hoping for a gold medal, they have to stick their landings.

Using cutting-edge theoretical calculations performed at NERSC, researchers at Berkeley Lab’s Molecular Foundry have predicted fascinating new properties of lithium—a light alkali metal that has intrigued scientists for two decades with its remarkable diversity of physical states at high pressures.

“Under standard conditions, lithium is a simple metal that forms a textbook crystalline solid. However, scientists have shown that when you put a lithium crystal under pressure, the atomic structure changes and, somewhat counterintuitively, its conductivity drops, becoming less metallic,” said Stephanie Mack, a graduate student research assistant at Berkeley Lab and first author of the study, published in PNAS. “We’ve discovered it also becomes topological, with electronic properties similar to graphene.”

Topological materials are a recently discovered class of solids that display exotic properties, such as having insulating interiors yet highly conductive surfaces, even when deformed. They are exciting for potential applications in next-generation electronics and quantum information science. According to coauthors Sinéad Griffin and Jeff Neaton, lithium becomes topological at high but experimentally achievable pressures, comparable to one-quarter of the pressure at the Earth’s center.

Continue reading “Lithium doesn’t crack under pressure, it transforms” »

There’s a known rule-breaker among materials, and a new discovery by an international team of scientists adds more evidence to back up the metal’s nonconformist reputation. According to a new study led by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and at the University of California, Berkeley, electrons in vanadium dioxide can conduct electricity without conducting heat.

The findings, to be published in the Jan. 27 issue of the journal Science, could lead to a wide range of applications, such as thermoelectric systems that convert waste heat from engines and appliances into electricity.

For most metals, the relationship between electrical and thermal conductivity is governed by the Wiedemann-Franz Law. Simply put, the law states that good conductors of electricity are also good conductors of heat. That is not the case for metallic vanadium dioxide, a material already noted for its unusual ability to switch from an insulator to a metal when it reaches a balmy 67 degrees Celsius, or 152 degrees Fahrenheit.

Continue reading “For this metal, electricity flows, but not the heat” »

Arindam Banerjee, an associate professor of mechanical engineering and mechanics at Lehigh University, studies the dynamics of materials in extreme environments. He and his team have built several devices to effectively investigate the dynamics of fluids and other materials under the influence of high acceleration and centrifugal force.

One area of interest is Rayleigh-Taylor instability, which occurs between materials of different densities when the density and pressure gradients are in opposite directions creating an unstable stratification.

“In the presence of gravity—or any accelerating field—the two materials penetrate one another like ‘fingers,’” says Banerjee.

Continue reading “Behold the mayo: Experiments reveal ‘instability threshold’ of elastic-plastic material” »

New research from the laboratory of Ozgur Sahin, associate professor of biological sciences and physics at Columbia University, shows that materials can be fabricated to create soft actuators—devices that convert energy into physical motion—that are strong and flexible, and, most important, resistant to water damage.

“There’s a growing trend of making anything we interact with and touch from materials that are dynamic and responsive to the environment,” Sahin says. “We found a way to develop a material that is water-resistant yet, at the same time, equipped to harness water to deliver the force and motion needed to actuate mechanical systems.”

The research was published online May 21 in Advanced Materials Technologies.

Continue reading “Robots activated by water may be the next frontier” »

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Researchers have created carbon nanosheets for use as supercapacitors with waste hemp fibres, and can do this at 1/1000th of the cost of graphene!

University of Chicago scientists are part of an international research team that has discovered superconductivity—the ability to conduct electricity perfectly—at the highest temperatures ever recorded.

This device helps builders create high quality concrete via Carmix Metalgalante.