Lifeboat Foundation

Researchers have developed an automatic drawing machine that uses pens and pencils to draw metamaterials onto paper. They demonstrated the new approach by using it to make three metamaterials that can be used to manipulate the microwave region of the electromagnetic spectrum.

Metamaterials are artificially engineered composite materials that derive their properties from patterned microstructures, rather than the chemical composition of the materials themselves. The exact shape, geometry, size, orientation and arrangement of the structures can be used to manipulate electromagnetic waves in ways that aren’t possible with conventional materials.

“Metamaterials, especially those used as absorbers, generally need to be thin, lightweight, wide and strong, but it isn’t easy to create thin and lightweight devices using traditional substrates,” said research team leader Junming Zhao from Nanjing University in China. “Using paper as the substrate can help meet these requirements while also lending itself to metasurfaces that conform to a surface or that are mechanically reconfigurable.”

CarbiCrete.

A key ingredient in concrete has always been cement, the production of which accounts for around 8 percent of the world’s greenhouse gas (GHG) emissions. While it may be tempting to think we are living in the age of plastic—after all, we have generated around 8 billion tonnes of plastic over the past 60 years and it turns out that the cement sector produces more than 30 billion tonnes of concrete each year.

Osaka Metropolitan University scientists have successfully developed a new positive electrode material Na₂FeS₂, consisting of sodium, iron, and sulfur. During testing, batteries using the Na₂FeS₂ positive electrode had a high energy storage capacity and could be charged and discharged for more than 300 cycles. Because the Na₂FeS₂ is made of abundant inexpensive elements, it is expected to be used in all-solid-state sodium batteries with higher capacity and lower costs.

The demand for high energy density rechargeable batteries, such as lithium-ion batteries, increases every year, as society shifts toward becoming carbon neutral. Sodium-ion batteries—which have a resource advantage over lithium-ion batteries —are attracting more attention, as cheap new high-performance materials continue to be developed.

A research group led by Associate Professor Atsushi Sakuda, President Masahiro Tatsumisago, and Professor Akitoshi Hayashi, at the Graduate School of Engineering, Osaka Metropolitan University, has successfully developed a new positive electrode, made of Na₂FeS₂, for all-solid-state sodium batteries. The batteries have a high energy storage capacity, high reversibility and use inexpensive elements that are readily available.

In the southern sky shine two smudges, known as the Large and Small Magellanic Clouds. They are satellite galaxies of the much larger Milky Way, and one of their qualities has puzzled scientists. As the Clouds tumble through space, the Milky Way should be exerting enough gravitational force to knock loose their star-making material. But the smaller galaxies are still building new stars. A study published Wednesday in the journal Nature finally explains it.

What they did — “A lot of people were struggling to explain how these streams of material could be there,” Dhanesh Krishnarao, assistant professor at Colorado College and lead author of the new study, says in a NASA description of the paper. “If this gas was removed from these galaxies, how are they still forming stars?”

Structural defects in metal”“organic frameworks can be exploited to tune material properties. In the case of UiO-66 material, they may change its nature from hydrophobic to…

For billions of years, the Large and Small Magellanic Clouds – the Milky Way’s largest satellite galaxies – have followed a perilous journey. Orbiting one another as they are pulled in toward our home galaxy, they have begun to unravel, leaving behind trails of gaseous debris. And yet these dwarf galaxies remain intact, with ongoing vigorous star formation, leaving astronomers baffled.

“A lot of people were struggling to explain how these streams of material could be there,” said Dhanesh Krishnarao, assistant professor at Colorado College. “If this gas was removed from these galaxies, how are they still forming stars?”

A team of astronomers led by Krishnarao has finally found the answer, with the help of data from NASA.

Standard silkworm silk has been made stronger than spider’s silk, one of the toughest materials known, by bathing it with metals and respinning it.

Some solid materials have a memory of how they have previously been stretched out, which impacts how they respond to these kinds of deformations in the future. A new Penn State study lends insight into memory formation in the foams and emulsions common in food products and pharmaceuticals and provides a new method to erase this memory, which could guide how materials are prepared for future use.

“A crease in a piece of paper serves as a memory of being folded or crumpled,” said Nathan Keim, associate research professor of physics at Penn State who led the study. “A lot of other materials form memories when they are deformed, heated up, or cooled down, and you might not know it unless you ask the right questions. Improving our understanding of how to write, read, and erase memories provides new opportunities for diagnostics and programming of materials. We can find out the history of a material by doing some tests or erase a material’s memory and program a new one to prepare it for consumer or industrial use.”

The researchers studied memory in a type of material called disordered solids, which have particles that are often erratically arranged. For example, ice cream is a disordered solid made up of a combination of ice crystals, fat droplets, and air pockets mixed together in a random way. This is in stark contrast to materials with “crystalline structures,” with particles arranged in highly ordered rows and columns. Disordered solids are common in food sciences, consumer products, and pharmaceuticals and include foams like ice cream and emulsions like mayonnaise.

Add analog and air-driven to the list of control system options for soft robots.

In a study published online this week, robotics researchers, engineers and materials scientists from Rice University and Harvard University showed it is possible to make programmable, nonelectronic circuits that control the actions of soft robots by processing information encoded in bursts of compressed air.

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