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Category: materials

A solid-state battery, where the liquid electrolyte that carries the charge is swapped out for a solid alternative, promises a number of performance benefits over today’s solutions, but there are a few problems to solve first. Scientists at Brown University are reporting a new design that overcomes some of the key hurdles, using a delicate mix of ceramics and the wonder material graphene to produce the toughest solid electrolyte to date.

As the solution that carries the lithium ions back and forth between the anode and cathode while the battery is charged and discharged, liquid electrolytes play an important role in the function of today’s lithium-ion batteries. But these highly volatile liquids bring a risk of fire when the battery short circuits, so there is room for improvement in terms of safety.

Beyond that, alternative electrolytes could offer greater energy density and even allow for other components of the battery to be upgraded, too. For example, the anode is typically made out of copper and graphite, but scientists believe a solid electrolyte would enable the battery to function with a pure lithium anode, something that could break the “energy-density bottleneck,” according to one recently published study.

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New research on the two-dimensional (2-D) material graphene has allowed researchers to create smart adaptive clothing which can lower the body temperature of the wearer in hot climates.

A team of scientists from the University of Manchester’s National Graphene Institute have created a prototype garment to demonstrate dynamic thermal radiation control within a piece of clothing by utilising the remarkable thermal properties and flexibility of graphene. The development also opens the door to new applications such as, interactive infrared displays and covert infrared communication on textiles.

The human body radiates energy in the form of electromagnetic waves in the (known as blackbody radiation). In a hot climate it is desirable to make use the full extent of the infrared radiation to lower the body which can be achieved by using infrared-transparent textiles. As for the opposite case, infrared-blocking covers are ideal to minimise the energy loss from the body. Emergency blankets are a common example used to deal with treating extreme cases of body temperature fluctuation.

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Scientists at the National Institute of Standards and Technology (NIST) and the Massachusetts Institute of Technology (MIT) have demonstrated a potentially new way to make switches inside a computer’s processing chips, enabling them to use less energy and radiate less heat.

The team has developed a practical technique for controlling magnons, which are essentially waves that travel through and can carry information. To use magnons for information processing requires a switching mechanism that can control the transmission of a magnon signal through the device.

While other labs have created systems that carry and control magnons, the team’s approach brings two important firsts: Its elements can be built on silicon rather than exotic and expensive substrates, as other approaches have demanded. It also operates efficiently at room temperature, rather than requiring refrigeration. For these and other reasons, this new approach might be more readily employed by .

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Circa 2015

Move over, graphene — you’re not the only miracle material in town. Australian researchers have discovered that diamond nanothreads (one-dimensional diamond crystals capped with hydrogen) could be extremely strong. While scientists thought they were brittle when announced just a month ago, it turns out that they become supremely flexible (and thus durable) when you introduce the right kinds of defects. You could create nanoscopic structures that are just as strong as you need them to be, with a ‘perfect’ mix of bendy and rigid shapes.

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Blobs of hot, dense material that curl around Earth’s core are much more widespread than previous research suggests.

A new method of analysing earthquake data has found even more of the previously detected continent-sized zones at the boundary between the planet’s core and mantle.

We still don’t know what these blobs are — they could be magma, molten iron leaking from the core, or something else — but with a more complete, detailed map of where they are, we can better understand the geological processes occurring deep inside Earth’s interior.

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Frequency multipliers, circuits that can produce signals with multiple frequencies, are essential components for a number of technological tools, particularly wireless communications systems. Most existing multipliers, however, are built using filtering and amplification circuits that are bulky and rapidly drain a lot of power.

Researchers at NaMLab in Germany have recently devised a single ferroelectric field-effect transistor that can serve both as a full-wave rectifier and frequency multiplier. The device they developed, presented in a paper published in Nature Electronics, is fully reconfigurable and energy-efficient, as it can be used in isolation, not requiring any additional circuits.

“Our institute (NaMLab) has been doing research on ferroelectric hafnium oxide (HfO2) since this material’s ferroelectric properties were discovered in 2007,” Halid Mulaosmanovic, one of the researchers who carried out the study, told TechXplore. “An attractive electronic device that can be made using this material is a ferroelectric field-effect transistor (FeFET), which resembles conventional logic transistors, but has a ferroelectric layer in the gate stack.”

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Paved roads are nice to look at, but they’re easily damaged and costly to repair. Erik Schlangen demos a new type of porous, asphalt made of simple materials with an astonishing feature: When cracked, it can be “healed” by induction heating. (Filmed at TEDxDelft.)

TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world’s leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design — plus science, business, global issues, the arts and much more.
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Three-dimensional graphene network is a promising structure for improving both the mechanical properties and functional capabilities of reinforced polymer and ceramic matrix composites. However, direct application in a metal matrix remains difficult due to the reason that wetting is usually unfavorable in the carbon/metal system. Here we report a powder-metallurgy based strategy to construct a three-dimensional continuous graphene network architecture in a copper matrix through thermal-stress-induced welding between graphene-like nanosheets grown on the surface of copper powders. The interpenetrating structural feature of the as-obtained composites not only promotes the interfacial shear stress to a high level and thus results in significantly enhanced load transfer strengthening and crack-bridging toughening simultaneously, but also constructs additional three-dimensional hyperchannels for electrical and thermal conductivity. Our approach offers a general way for manufacturing metal matrix composites with high overall performance.

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