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Category: materials – Page 165

Creating a battery that can withstand repeated cycles of heating and cooling is no small feat. Temperature fluctuations cause the battery to expand and contract, and the researchers had to identify resilient materials that could tolerate these changes. “What we’ve seen before is a lot of active research to make sure you do not have to go through that thermal cycle,” says Vince Sprenkle, a strategic advisor in energy storage at PNNL and a co-author of the new paper. “We’re saying, ‘We want to go through it, and we want to be able to survive and use that as a key feature.’”

The result is a rechargeable battery made from relatively inexpensive materials that can store energy for extended periods. “It’s a great example of a promising long-duration energy-storage technology,” says Aurora Edington, policy director of the electricity industry association GridWise Alliance, who was not involved with this research. “I think we need to support those efforts and see how far we can take them to commercialization.”

The technology could be particularly useful in a place such as Alaska, where near-constant summer sunlight coincides with relatively low rates of energy use. A battery that can store energy for months could allow abundant summer solar power to fulfill winter electricity needs. “What is so attractive about the freeze-thaw battery is that seasonal shifting capability,” says Rob Roys, chief innovation officer at Launch Alaska, a nonprofit organization that works to accelerate the deployment of climate technologies in the state. Roys hopes to pilot the PNNL battery in a remote part of his state.

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Admatec has steadily been increasing its 3D printing capabilities, taking its slurry-based digital light processing (DLP) process further. First it expanded from resins loaded with ceramic particles to those loaded with metal particles. It then increased the build volume of its Admaflex300 3D printer. Now, the company has introduced a new integrated debinding and sintering furnace with a larger work volume.

The majority of ceramic 3D printing processes rely on the use of a photopolymer slurry loaded with ceramic particles. Once printed, these green parts first go through a debinding process, in which the photopolymer material is removed, followed by sintering, causing the part to become fully dense.

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Most craters are circular in shape due to material ejecting out in all directions as a result of an impact. Below is a group of impact craters in Noachis Terra, a large region in Mars’ southern hemisphere. These are all classified as simple craters, which are small bowl-shaped, smooth-walled craters.

Complex craters, on the other hand, are large craters with complicated features, such as terraces, central peaks, and rims and walls their own features. Oblong craters, like the one in the lead image — which is also located in Noachis Terra — can sometimes be created by impacts striking the surface at a very low grazing angle.

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Engineers at MIT have developed an ultra-thin speaker that could be used to make entire surfaces produce sound. The unique design should be energy efficient and easy to produce at scale, the team says.

In a basic sense, speakers work by vibrating a membrane, which manipulates the air above it to produce sound waves. In speakers commonly found in audio systems or headphones, that’s done using electrical currents and magnetic fields.

But in recent years scientists have developed ways to achieve similar results in much slimmer devices. Thin film speakers work using piezoelectric materials, which vibrate in response to the application of a voltage. These have been used in phones and TVs, and even experimentally to create speakers out of things as unusual as flags.

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Saturn’s moon Titan looks very much like Earth from space, with rivers, lakes, and seas filled by rain tumbling through a thick atmosphere. While these landscapes may look familiar, they are composed of materials that are undoubtedly different—liquid methane streams streak Titan’s icy surface and nitrogen winds build hydrocarbon sand dunes.

The presence of these materials—whose are vastly different from those of silicate-based substances that make up other known sedimentary bodies in our solar system—makes Titan’s landscape formation enigmatic. By identifying a process that would allow for hydrocarbon-based substances to form or bedrock depending on how often winds blow and streams flow, Stanford University geologist Mathieu Lapôtre and his colleagues have shown how Titan’s distinct dunes, plains, and labyrinth terrains could be formed.

Titan, which is a target for space exploration because of its potential habitability, is the only other body in our solar system known to have an Earth-like, seasonal liquid transport cycle today. The new model, published in Geophysical Research Letters April 25, shows how that seasonal cycle drives the movement of grains over the moon’s surface.

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Researchers at the University of Freiburg have worked with colleagues at the University of California, Berkeley to come up with a novel means of rapidly 3D printing complex glass parts at a microscopic scale.

Known as ‘Microscale Computed Axial Lithography’ (Micro-CAL), this approach involves exposing resin to 2D light images of a desired shape from multiple angles, which when they overlap, trigger polymerization. When used to print the Glassomer material previously honed at Freiburg, the team say their layer-free process has the potential to unlock devices with new microfluidic or micro-optical functionality.

“For the first time, we were able to print glass with structures in the range of 50 micrometers in just a few minutes, which corresponds roughly to the thickness of a hair,” explains the University of Freiburg’s Dr. Frederik Kotz-Helmer. The ability to manufacture such components at high speed and with great geometric freedom will enable new functions and more cost-effective products in the future.”

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