Our flexible processors can now use bendable RAM

Extreme close-up photograph of tweezers holding a flexible computer component.

Enlarge / Try doing that with your RAM. (credit: A.I. Khan and A. Daus.)

A few months ago, we brought news of a bendable CPU, termed Plastic ARM, that was built of amorphous silicon on a flexible substrate. The use cases for something like this are extremely low-powered devices that can be embedded in clothing or slapped on the surface of irregular objects, allowing them to have a small amount of autonomous computing. But to meet the low power requirements, a minimalist processor is not enough—all the components have to sip power as well. And that makes for a poor fit for traditional RAM technology, which needs power to maintain the state of the memory.

But a group from Stanford now has that covered. The researchers have built a form of flexible phase-change memory, which is closer in speed to normal RAM than flash memory but requires no power to maintain its state. And, while their work was initially focused on getting something that’s flexible to work, the principles they uncovered during their work should apply to phase-change memory in general.

A change of phase

People have made flexible forms of memory before, including flash and ferroelectric RAM, and resistive RAM can be made from materials that are also bendable. But phase-change memory has myriad advantages. It works by connecting two electrodes via a material that can form crystalline and amorphous states, depending on how quickly it’s cooled down after heating. These two states differ in how well they conduct electricity, allowing them to be distinguished.

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#flexible-electronics, #materials-science, #memory, #phase-change-memory, #ram, #science

A Flexible Fabric Could Harden into a Temporary House or Bridge

Ancient chain mail served as an inspiration for a highly unusual material that might one day lead to such applications

— Read more on ScientificAmerican.com

#chemistry, #materials-science

PlasticARM is a 32-bit bendable processor

Image of the plasticARM processor, showing its dimensions and components.

Enlarge (credit: Biggs, et. al.)

Wearable electronics, like watches and fitness trackers, represent the next logical step in computing. They’ve sparked an interest in the development of flexible electronics, which could enable wearables to include things like clothing and backpacks.

Flexible electronics, however, run into a problem: our processing hardware is anything but flexible. Most efforts at dealing with that limitation have involved splitting up processors into a collection of smaller units, linking them with flexible wiring, and then embedding all the components in a flexible polymer. To an extent, it’s a throwback to the early days of computing, when a floating point unit might reside on a separate chip.

But a group within the semiconductor company ARM has now managed to implement one of the company’s smaller embedded designs using flexible silicon. The design works and executes all the instructions you’d expect from it, but it also illustrates the compromises we have to make for truly flexible electronics.

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#arm, #computer-science, #materials-science, #processor, #science

New fabric passively cools whatever it’s covering—including you

Image of a white, Ars Technica branded shirt.

Enlarge / Like this, but even cooler. (credit: Ars Technica)

Rising temperatures around the world run the risk of creating a dangerous cycle where more people get air conditioning, which causes energy demand to surge and leads to higher carbon emissions, which makes temperatures rise even more. Renewable power is one option for breaking that cycle, but people have also been studying materials that enable what’s called passive cooling. Without using energy, these materials take heat from whatever they’re covering and radiate it out to space.

Most of these efforts have focused on building materials, with the goal of creating roofs that can keep buildings a few degrees cooler than the surrounding air. But now a team based in China has taken the same principles and applied them to fabric, creating a vest that keeps its users about 3º C cooler than they would be otherwise.

Built to chill

Whenever something’s out in the sunlight, it’s going to absorb some of those photons, which will get converted into heat. That heat can then be radiated back out in infrared wavelengths. The problem is that this doesn’t actually cool things down much. Lots of the gasses in the atmosphere immediately absorb the infrared light, trapping the energy as heat in the immediate vicinity of the object. If the object is a person, there’s the added issue of heat generated by their metabolism, which is also getting radiated away in the infrared at the same time.

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#cooling, #fabric, #heat, #infrared, #materials-science, #science

Mighty morphin’ flat-packed pasta takes on 3D shapes as it cooks

Pasta comes in many shapes and sizes, which is part of its inherent delight. But all those irregular shapes tend to be inefficient when it comes to packaging. So what if you could buy your pasta of choice in a simple, compact 2D form and then watch it take on the desired final 3D shape as it cooks, thereby doubling the fun factor? Scientists at Carnegie-Mellon University (CMU) have figured out a simple mechanism to do just that, according to a new paper published in the journal Science Advances.

“We were inspired by flat-packed furniture and how it saved space, made storage easier, and reduced the carbon footprint associated with transportation,” said co-author Lining Yao, director of the Morphing Matter Lab at CMU’s School of Computer Science. “We decided to look at how the morphing matter technology we were developing in the lab could create flat-packed pastas that offered similar sustainability outcomes.” According to the team’s calculations, even if you pack macaroni pasta perfectly, you will still end up with as much as 67 percent of the volume being air. The ability to make flat pasta for shipping that takes on a specific 3D shape when cooked is one potential solution.

Yao and co-author Wen Wang, also at CMU, began experimenting with what they term “transformative appetite,” or shape-changing food, several years ago, inspired by their work with a bacterium that would shrink or expand in response to humidity—the same bacterium used to ferment soybeans to create natto, a popular Japanese breakfast dish that frankly smells a bit like aged cheese (and hence can be an acquired taste).

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#food-science, #materials-science, #mechanical-engineering, #pasta-science, #pasta-shapes, #science

Materials Zone raises $6M for its materials discovery platform

Materials Zone, a Tel Aviv-based startup that uses AI to speed up materials research, today announced that it has raised a $6 million seed funding round led by Insight Partners, with participation from crowdfunding platform OurCrowd.

The company’s platform consists of a number of different tools, but at the core is a database that takes in data from scientific instruments, manufacturing facilities, lab equipment, external databases, published articles, Excel sheets and more, and then parses it and standardizes it. Simply having this database, the company argues, is a boon for researchers, who can then also visualize it as needed.

Image Credits: Materials Zone

“In order to develop new technologies and physical products, companies must first understand the materials that comprise those products, as well as those materials’ properties,” said Materials Zone founder and CEO Dr. Assaf Anderson. “Understanding the science of materials has therefore become a driving force behind innovation. However, the data behind materials R&D and production has traditionally been poorly managed, unstructured, and underutilized, often leading to redundant experiments, limited capacity to build on past experience, and an inability to effectively collaborate, which inevitably wastes countless dollars and man-hours.”

Image Credits: Materials Zone

Before founding Materials Zone, Anderson spent time at the Bar Ilan University’s Institute for Nanotechnology and Advanced Materials, where he was the head of the Combinatorial Materials lab.

Assaf Anderson, Ph.D., founder and CEO of Materials Zone

Assaf Anderson, PhD, founder/CEO of Materials Zone. Image Credits: Materials Zone

“As a materials scientist, I have experienced R&D challenges firsthand, thereby gaining an understanding of how R&D can be improved,” Anderson said. “We developed our platform with our years of experience in mind, leveraging innovative AI/ML technologies to create a unique solution for these problems.”

He noted that in order to, for example, develop a new photovoltaic transparent window, it would take thousands of experiments to find the right core materials and their parameters. The promise of Materials Zone is that it can make this process faster and cheaper by aggregating and standardizing all of this data and then offer data and workflow management tools to work with it. Meanwhile, the company’s analytical and machine learning tools can help researchers interpret this data.


#artificial-intelligence, #insight-partners, #machine-learning, #materials-science, #materials-zone, #ml, #nanotechnology, #ourcrowd, #recent-funding, #science, #science-and-technology, #startups, #tel-aviv

Curran Biotech’s new nanocoating could prevent indoor transmission of COVID-19

A new nanocoating from Curran Biotech could dramatically improve air filtration to prevent the spread of COVID-19 indoors.

Their Capture Coating technology acts as a supplement to any household or commercial HVAC system by bonding to the filter fibers, giving them greater hydrophobic properties. This combined effect prevents virus-carrying droplets from traveling through the filter fibers, which, without the treatment, only prevent some viral transmission.

“’Capture Coating’ is designed to mitigate and significantly decrease viral transmission of COVID-19 through specified air filtration media by forming a breathable, flexible, non-leaching, water-repellent barrier against aqueous respiratory droplets that act as virion carriers that can potentially be recirculated through conventional air-filters,” wrote Curran Biotech founder and University of Houston physics professor Shay Curran in an email. Despite the molecular complexity of the coating, the product itself can simply be sprayed onto an HVAC system’s filter.

This new droplet-targeting coating is an improvement over current filtration methods, which typically only target dry molecules. Not only do those methods often have at least some potential of viral droplet transmission, but current solutions to improve them aren’t always energy efficient.

“In the world where energy management is very important, that means recycling the same air in the building with the risk of cross contamination,” wrote Curran. “Taking outside air is one way to dilute the air, but that means we also lose a huge amount in terms of energy, and still don’t solve the problem of taking the virus away from places where people congregate.”

Indoor air ventilation remains an important tool in mitigating the spread of COVID-19 across schools, small businesses, and other public buildings, but updating old HVAC systems to the recommended CDC standards can be costly. Curran hopes that his company’s approach can help address this issue, as the Capture Coating requires only a simple spray, rather than a completely new system of filters. “That really means for a few dollars when used on a standard issue MERV8, you can have huge indoor protection and stop its spread throughout the building,” he wrote.

Because of the nature of the nanocoating, Curran’s technology can help prevent viral droplet transmission long after the end of the COVID-19 pandemic. The hydrophobic qualities of the coating prevent respiratory droplets from actions like sneezing or coughing from passing through the filter, while the HVAC system itself retains its normal capabilities for dry molecule filtration. With the Capture Coating, common droplet-transmitting viruses like the flu or cold will also be filtered out of circulation.

Similarly, the nanocoating would work in preventing transmission of any variant of the COVID-19 virus, as all of those variants also undergo droplet transmission. “It does not mean we get away from taking precautions such as hand washing, wearing masks etc, but it does mean we can work indoors far more safely,” wrote Curran.

So far, Curran Biotech’s Capture Coating technology is in use in 11 states, and will soon be announcing partnerships with distributors and filter companies to directly provide consumers with coated filters. Curran wrote that the company has also had successful trials of the technology in New York City, and hopes to expand use of the product even further across businesses and institutions around the country.

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#biotech, #covid, #covid-19, #health, #houston, #materials-science, #nanotechnology, #science, #startup, #tc, #transmission

Kombucha tea inspires new “living material” for biosensing applications

Brewing kombucha tea. Note the trademark gel-like layer of SCOBY (symbiotic culture of bacteria and yeast).

Enlarge / Brewing kombucha tea. Note the trademark gel-like layer of SCOBY (symbiotic culture of bacteria and yeast). (credit: Olga Pankova/Getty Images)

Kombucha tea is all the rage these days as a handy substitute for alcoholic beverages and for its supposed health benefits. The chemistry behind this popular fermented beverage is also inspiring scientists at MIT and Imperial College London to create new kinds of tough “living materials” that could one day be used as biosensors, helping purify water or detect damage to “smart” packing materials, according to a recent paper published in Nature Materials.

You only need three basic ingredients to make kombucha. Just combine tea and sugar with a kombucha culture known as a SCOBY (symbiotic culture of bacteria and yeast), aka the “mother,” also known as a tea mushroom, tea fungus, or a Manchurian mushroom. (It’s believed that kombucha tea originated in Manchuria, China, or possibly Russia.) It’s basically akin to a sourdough starter. A SCOBY is a firm, gel-like collection of cellulose fiber (biofilm), courtesy of the active bacteria in the culture, creating the perfect breeding ground for the yeast and bacteria to flourish. Dissolve the sugar in non-chlorinated boiling water, then steep some tea leaves of your choice in the hot sugar water before discarding them.

Once the tea cools, add the SCOBY and pour the whole thing into a sterilized beaker or jar. Then cover the beaker or jar with a paper towel or cheesecloth to keep out insects, let it sit for two to three weeks, and voila! You’ve got your own home-brewed kombucha. A new “daughter” SCOBY will be floating right at the top of the liquid (technically known in this form as a pellicle). But be forewarned: it’s important to avoid contamination during preparation because drinking tainted kombucha can have serious, even fatal, adverse effects. And despite claims that drinking kombucha tea can treat aging, arthritis, cancer, constipation, diabetes, or even AIDS, to date there is no solid scientific evidence to back those claims.

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#biomaterials, #chemistry, #kombucha, #materials-science, #science, #scoby, #synthetic-biology

It’s the wombat’s strange intestines, not its anus, that produces cubed poo

cube shaped wombat dropping

Enlarge / Look at this lovely cube-shaped piece of poo, courtesy of the Australian bare-nosed wombat. (credit: Patricia J. Yang et al., 2021)

Scientists have been puzzling for decades over how the Australian bare-nosed wombat poops out neat little cubes of feces instead of tapered cylinders like pretty much all other animals. According to a new paper published in the journal Soft Matter, the secret lies in their intestines, which have varying stiff and soft regions that serve to shape the poo during the digestive process. Earlier preliminary findings by the same group won the 2019 Ig Nobel Physics Prize.

“Bare-nosed wombats are renowned for producing distinctive, cube-shaped poos. This ability to form relatively uniform, clean cut feces is unique in the animal kingdom,” said University of Tasmania wildlife ecologist Scott Carver, a co-author on the paper. “They place these feces at prominent points in their home range, such as around a rock or a log, to communicate with each other. Our research found that these cubes are formed within the last sections of the intestine—and finally proves that you really can fit a square peg through a round hole.”

Zoologist Eric Guiler first noted the unusual shape of wombat droppings in 1960, and to date, wombats are the only known animals to produce six-sided cube-shaped poo. It’s one of several examples of naturally occurring pattern formation, such as the columns of Ireland’s Giant’s Causeway (formed by cooling lava), or how vibrating membranes can make grains of sand form “Chladni figures.” But naturally occurring cube shapes are extremely rare. The Australian bare-nosed wombat (Vombatus ursinus) can pump out as many as 100 cube-shaped droppings a day.

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#biology, #biophysics, #materials-science, #physics, #science, #soft-matter, #wombat-poo

What’s the technology behind a five-minute charge battery?

Image of a set of battery racks.

Enlarge (credit: StoreDot)

Building a better battery requires dealing with problems in materials science, chemistry, and manufacturing. We do regular coverage of work going on in the former two categories, but we get a fair number of complaints about our inability to handle the third: figuring out how companies manage to take solutions to the science and convert them into usable products. So, it was exciting to see that a company called StoreDot that was claiming the development of a battery that would allow five-minute charging of electric vehicles was apparently willing to talk to the press.

Unfortunately, the response to our inquiries fell a bit short of our hopes. “Thank you for your interest,” was the reply, “we are still in pure R&D mode and cannot share any information or answer any questions at the moment.” Apparently, the company gave The Guardian an exclusive and wasn’t talking to anyone else.

Undeterred, we’ve since pulled every bit of information we could find from StoreDot’s site to figure out roughly what they were doing, and we went backwards from there to look for research we’ve covered previously that could be related. What follows is an attempt to piece together a picture of the technology and the challenges a company has to tackle to take research concepts and make products out of them.

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#batteries, #commercialization, #lithium-ion-battery, #materials-science, #science

New metamaterial merges magnetic memory and physical changes

Image of a polymer-based device with flexible parts.


For applications like robotics, there’s usually a clear division of labor between the processors that control the robot’s body and the actuators that actually control the physical changes of that body. But a new paper being released today blurs the lines between the two, using a magnetic switch in a way that both stores a bit representing the hardware’s state and alters the physical conformation of the hardware. In essence, it merges memory and physical changes.

This particular implementation doesn’t seem to be especially useful—it’s much too big to be a practical form of memory, and the physical changes are fairly limited. But the concept is intriguing, and it’s possible that someone more adept at creative thinking can find ways of modifying the concept to create a useful device.

A magnetic metamaterial?

A metamaterial is generally defined as a material that is structured so that it has properties that aren’t found in bulk mixes of its raw materials. A broad reading of that definition, however, would mean that a car is a metamaterial, which makes the definition near meaningless. The researchers behind the new device, based at Switzerland’s École Polytechnique Fedeŕale de Lausanne, claim their creation is a metamaterial, but it’s fairly large (roughly a cube three centimeters on a side) and has a number of distinct parts. I’d tend to call that a device rather than a material and will use that terminology here.

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#materials-science, #memory, #meta-materials, #metamaterials, #science

One piece of optical hardware performs massively parallel AI calculations

Image of a series of parallel lines in different colors.

Enlarge / The output of two optical frequency combs, showing the light appearing at evenly spaced wavelengths. (credit: ESO)

AI and machine-learning techniques have become a major focus of everything from cloud computing services to cell phone manufacturers. Unfortunately, our existing processors are a bad match for the sort of algorithms that many of these techniques are based on, in part because they require frequent round trips between the processor and memory. To deal with this bottleneck, researchers have figured out how to perform calculations in memory and designed chips where each processing unit has a bit of memory attached.

Now, two different teams of researchers have figured out ways of performing calculations with light in a way that both merges memory and calculations and allows for massive parallelism. Despite the differences in implementation, the hardware designed by these teams has a common feature: it allows the same piece of hardware to simultaneously perform different calculations using different frequencies of light. While they’re not yet at the level of performance of some dedicated processors, the approach can scale easily and can be implemented using on-chip hardware, raising the prospect of using it as a dedicated co-processor.

A fine-toothed comb

The new work relies on hardware called a frequency comb, a technology that won some of its creators the 2005 Nobel Prize in Physics. While a lot of interesting physics is behind how the combs work (which you can read more about here), what we care about is the outcome of that physics. While there are several ways to produce a frequency comb, they all produce the same thing: a beam of light that is composed of evenly spaced frequencies. So a frequency comb in visible wavelengths might be composed of light with a wavelength of 500 nanometers, 510nm, 520nm, and so on.

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#ai, #computer-science, #materials-science, #optical-computing, #science

How electric lighting changed our sleep, and other stories in materials science

A housewife proudly presents her indispensable Pyrex kitchenware (1955). Ainissa Ramirez tells the story of its invention, and how it molded human behavior in turn, in her book, <em>The Alchemy of Us</em>.

Enlarge / A housewife proudly presents her indispensable Pyrex kitchenware (1955). Ainissa Ramirez tells the story of its invention, and how it molded human behavior in turn, in her book, The Alchemy of Us. (credit: Chaloner Woods/Getty Images)

There’s rarely time to write about every cool science-y story that comes our way. So this year, we’re once again running a special Twelve Days of Christmas series of posts, highlighting one science story that fell through the cracks in 2020, each day from December 25 through January 5. Today: Kick off the new year with physicist and “science evangelist” Ainissa Ramirez as she tells engaging stories about materials science, the technologies it enables, and how those technologies impact human behavior in her book, The Alchemy of Us.

The American 19th century entrepreneur Thomas Edison is perhaps most famous for his development of the incandescent light bulb, but few people likely know that part of his inspiration came from an obscure fellow inventor in Connecticut named William Wallace. Edison visited Wallace’s workshop on September 8, 1878, to check out the latter’s prototype “arc light” system. Edison was impressed, but he thought he could improve on the system, which used a steam-powered dynamo to produce an incredibly bright light—much too bright for household use, more akin to outdoor floodlights. The result was the gentle glow of the incandescent bulb.

Other inventors had come up with versions of an incandescent lamp prior to Edison, but the Menlo Park wizard discovered an excellent incandescent material in carbonized bamboo that lasted for over 1000 hours, and also devised a fully integrated system of electric lighting to drive adoption of this new technology. Edison found a material he could shape to his needs. But electric lighting would in turn shape how people slept, as physicist and self-described “science evangelist” Ainissa Ramirez explains in her book, The Alchemy of Us: How Humans and Matter Transformed One Another, released in April.

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#12-days-of-christmas, #books, #gaming-culture, #materials-science, #physics, #popular-science-books, #science

New battery chemistry results in first rechargeable zinc-air battery

Image of three chunks of zinc metal.

Enlarge (credit: Wikimedia Commons)

Most of the disposable batteries you’ll come across are technically termed alkaline batteries. They work at high pH and typically use zinc as the charge carrier. Zinc is great because it’s very cheap, can be used to make one of the two electrodes, and, in the right context, allows the use of air at the other electrode. These latter two items simplify the battery, allowing it to be more compact and lighter weight—so far, attempts to do similar things with lithium batteries have come up short.

The problem with all of this is that the batteries are disposable for a good reason: the chemistry of discharging doesn’t really allow things to work in reverse. Carbon dioxide from the air reacts with the electrolyte, forming carbonates that block one electrode. And the zinc doesn’t re-deposit neatly on the electrode it came from, instead creating spiky structures called dendrites that can short out the battery.

Now, an international team has figured out how to make zinc batteries rechargeable. The answer, it seems, involves getting rid of the alkaline electrolyte that gave the batteries their name.

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#batteries, #chemistry, #materials-science, #science, #zinc

Wooden satellites an intriguing idea, but won’t solve space junk problems

A cube covered in solar panels orbiting above clouds.

Enlarge / An experimental satellite, not made of wood, that was used to test ideas for orbital junk removal. (credit: NASA)

We here at Ars were somewhat surprised to stumble across a BBC headline indicating that a university-industry partnership in Japan was working on developing wooden satellites. The plan is less insane than it sounds—wood is a remarkable material that’s largely unappreciated because of its ubiquity. But most of the reasons to shift to wood give in the coverage of the plan completely misses the mark.

To the degree that there is a plan, at least. According to the BBC and other coverage, the partnership is between Kyoto University and a company called Sumitomo Forestry. But neither the university nor the company has any information on the project available on the English-language versions of their websites. The BBC article gets all its quotes from Takao Doi, who’s currently faculty at Kyoto University. According to Doi, the collaboration is on track to be manufacturing flight models of wooden satellites by 2023.

While wood may seem like a horrific fit for the harsh environment of space, the idea may seem less insane if you think of wood in terms of its structural composition: a mix of two robust polymers, cellulose and lignin. The strength and durability of wood depends heavily on the ratio of these polymers and what’s also present in the mix with them. But it’s also possible to physically and chemically treat wood to alter its properties further. One version of wood was as strong as aluminum by some measures, and had some interesting additional properties. And a forestry company can be expected to have extensive knowledge of how to process wood.

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#materials-science, #satellite, #science, #space, #space-junk, #wood

Phosphorus equivalent of grapheme makes reconfigurable transistors

Image of two sets of bar graphs.

Enlarge / One gate, two behaviors. (credit: Peng Wu et al.)

At the moment, our processors are built on silicon. But fundamental limits on what can be done with that material has researchers eyeing ways to use materials that have inherently small features, like nanotubes or atomically thin materials. At least in theory, these will let us do what we’re now doing, just more efficiently and/or with physically smaller features.

But can these materials allow us to do things that silicon can’t? The answer appears to be yes, based on research published earlier this week. In it, the researchers describe transistors that can be reconfigured on the fly so that they perform completely different operations. They suggest this can be useful for security, as it would keep bad actors from figuring out how security features are implemented.

Doping vs. security

The researchers, based at Perdue and Notre Dame, lay out an argument for why this sort of reconfigurable circuitry could have security implications. It comes down to the materials science of silicon transistors. They require areas of silicon that either hold negative or positive charge (creatively named p- or n-type semiconductors). These are created by doping, or adding small amounts of certain elements to the silicon. This is done during the manufacturing, and the doping is locked into place at that point. This means that the operation of individual transistors is locked into place when the chip is made.

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#atomically-thin-materials, #black-phosphorus, #electronics, #materials-science, #science, #transistor

Saving Notre Dame chronicles effort to rebuild France’s famous cathedral

The iconic spire collapses as smoke and flames engulf the Notre Dame Cathedral in Paris on April 15, 2019.

Enlarge / The iconic spire collapses as smoke and flames engulf the Notre Dame Cathedral in Paris on April 15, 2019. (credit: Geoffroy van der Hasselt/AFP via Getty Images)

On April 15, 2019, the world watched in horror as the roof of the famed Notre Dame cathedral in Paris caught fire. The blaze spread rapidly, and for several nail-biting hours, it seemed this 850-year-old Gothic masterpiece might be destroyed entirely. Firefighters finally gained the upper hand in the wee hours of the following morning. Almost immediately after the fire had been extinguished, French President Emmanuel Macron vowed to rebuild Notre Dame.

But first, the badly damaged structure had to be shored up and stabilized, and interdisciplinary teams of scientists, engineers, architects, and master craftspeople assembled to determine the best way to proceed with the restoration. That year-long process—headed up by Chief Architects Philippe Villeneuve and Remi Fromont— is the focus of a new NOVA documentary premiering tonight on PBS. Saving Notre Dame follows various experts as they study the components of the cathedral’s iconic structure to puzzle out how best to repair it.

Director Joby Lubman was among those transfixed in horror when the fire broke out, staying up much of the night as the cathedral burned, until it became clear that the structure would ultimately survive, albeit badly damaged. In the office the next morning, “Everyone was a bit shell-shocked talking about it,” he told Ars. “And it might sound opportunistic, but I thought, ‘The restoration of this icon is going to be quite something to document.'”

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#architecture, #conservation, #documentary, #gaming-culture, #history, #materials-science, #notre-dame, #nova, #pbs, #science

If recycling plastics isn’t making sense, remake the plastics

Image of a forklift surrounded by plastic bottles.

Enlarge / Workers sort plastic waste as a forklift transports plastic waste at Yongin Recycling Center in Yongin, South Korea. (credit: Bloomberg/Getty Images)

A few years back, it looked like plastic recycling was set to become a key part of a sustainable future. Then, the price of fossil fuels plunged, making it cheaper to manufacture new plastics. Then China essentially stopped importing recycled plastics for use in manufacturing. With that, the bottom dropped out of plastic recycling, and the best thing you could say for most plastics is that they sequestered the carbon they were made of.

The absence of a market for recycled plastics, however, has also inspired researchers to look at other ways of using them. Two papers this week have looked into processes that enable “upcycling,” or converting the plastics into materials that can be more valuable than the freshly made plastics themselves.

Make me some nanotubes

The first paper, done by an international collaboration, actually obtained the plastics it tested from a supermarket chain, so we know it works on relevant materials. The upcycling it describes also has the advantage of working with very cheap, iron-based catalysts. Normally, to break down plastics, catalysts and the plastics are heated together. But in this case, the researchers simply mixed the catalyst and ground up plastics and heated the iron using microwaves.

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#catalysts, #chemistry, #materials-science, #plastics, #recycling, #science

High pressure superconductors reach room temperature

Image of a blue box surrounded by hardware lit in green.

Enlarge / Equipment including a diamond anvil cell (blue box) and laser arrays in the lab of Ranga Dias at the University of Rochester. Undoubtedly, they cleaned up the typical mess of cables and optical hardware before taking the photo.

In the period after the discovery of high-temperature superconductors, there wasn’t a good conceptual understanding of why those compounds worked. While there was a burst of progress towards higher temperatures, it quickly ground to a halt, largely because it was fueled by trial and error. Recent years brought a better understanding of the mechanisms that enable superconductivity, and we’re seeing a second burst of rapidly rising temperatures.

The key to the progress has been a new focus on hydrogen-rich compounds, built on the knowledge that hydrogen’s vibrations within a solid help encourage the formation of superconducting electron pairs. By using ultra-high pressures, researchers have been able to force hydrogen into solids that turned out to superconduct at temperatures that could be reached without resorting to liquid nitrogen.

Now, researchers have cleared a major psychological barrier by demonstrating the first chemical that superconducts at room temperature. There are just two catches: we’re not entirely sure what the chemical is, and it only works at 2.5 million atmospheres of pressure.

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#chemistry, #materials-science, #physics, #science, #superconductivity

Engineering a battery fast enough to make recharging like refueling

Layers of phosphorene sheets form black carbon.

Enlarge / Layers of phosphorene sheets form black carbon. (credit: Wikimedia Commons)

Right now, electric vehicles are limited by the range that their batteries allow. That’s because recharging the vehicles, even under ideal situations, can’t be done as quickly as refueling an internal combustion vehicle. So far, most of the effort on extending the range has been focused on increasing a battery’s capacity. But it could be just as effective to create a battery that can charge much more quickly, making a recharge as fast and simple as filling your tank.

There are no shortage of ideas about how this might be arranged, but a paper published earlier this week in Science suggests an unusual way that it might be accomplished: using a material called black phosphorus, which forms atom-thick sheets with lithium-sized channels in it. On its own, black phosphorus isn’t a great material for batteries, but a Chinese-US team has figured out how to manipulate it so it works much better. Even if black phosphorus doesn’t end up working out as a battery material, the paper provides some insight into the logic and process of developing batteries.

Paint it black

So, what is black phosphorus? The easiest way to understand it is by comparisons to graphite, a material that’s already in use as an electrode for lithium-ion batteries. Graphite is a form of carbon that’s just a large collection of graphene sheets layered on top of each other. Graphene, in turn, is a sheet formed by an enormous molecule formed by carbon atoms bonded to each other, with the carbons arranged in a hexagonal pattern. In the same way, black phosphorus is composed of many layered sheets of an atom-thick material called phosphorene.

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#batteries, #chemistry, #green, #materials-science, #science

Chitin could be used to build tools and habitats on Mars, study finds

A figurine of an astronaut stands next to a block.

Enlarge / Scientists mixed chitin—an organic polymer found in abundance in arthropods, as well as fish scales—with a mineral that mimics the properties of Martian soil to create a viable new material for building tools and shelters on Mars. (credit: Javier G. Fernandez)

Space aficionados who dream of one day colonizing Mars must grapple with the stark reality of the planet’s limited natural resources, particularly when it comes to building materials. A team of scientists from the Singapore University of Technology and Design discovered that, using simple chemistry, the organic polymer chitin—contained in the exoskeletons of insects and crustaceans—can easily be transformed into a viable building material for basic tools and habitats. This would require minimal energy and no need for transporting specialized equipment. The scientists described their experiments in a recent paper published in the journal PLOS ONE.

“The technology was originally developed to create circular ecosystems in urban environments,” said co-author Javier Fernandez. “But due to its efficiency, it is also the most efficient and scalable method to produce materials in a closed artificial ecosystem in the extremely scarce environment of a lifeless planet or satellite.”

As we previously reported, NASA has announced an ambitious plan to return American astronauts to the Moon and establish a permanent base there, with an eye toward eventually placing astronauts on Mars. Materials science will be crucial to the Artemis Moon Program’s success, particularly when it comes to the materials needed to construct a viable lunar (or Martian) base. Concrete, for instance, requires a substantial amount of added water in order to be usable in situ, and there is a pronounced short supply of water on both the Moon and Mars. And transport costs would be prohibitively high. NASA estimates that it costs around $10,000 to transport just one pound of material into orbit. 

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#artemis-moon-program, #biochemistry, #biology, #biomimicry, #chitin, #mars, #materials-science, #nasa, #science, #space-colonization

This tiny reproduction of Girl With a Pearl Earring is “painted” with light

An illustration of how millions of nanopillars were used to control both the color and intensity of incident light, projecting a faithful reproduction of Johannes Vermeer's <em>Girl With a Pearl Earring</em>.

Enlarge / An illustration of how millions of nanopillars were used to control both the color and intensity of incident light, projecting a faithful reproduction of Johannes Vermeer’s Girl With a Pearl Earring. (credit: T. Xu/Nanjing University)

Scientists have fabricated tiny “nanopillars” capable of transmitting specific colors of light, at specific intensities, which hold promise for improved optical communication and anti-counterfeit measures for currency. For proof of concept, they decided to digitally reproduce Dutch master Johannes Vermeer’s famous painting Girl With a Pearl Earring—just painted in light instead of pigment. They discussed their work in a recent paper published in the journal Optica.

“The quality of the reproduction, capturing the subtle color gradations and shadow details, is simply remarkable,” said co-author Amit Agrawal, a researcher with the National Institute of Science and Technology (NIST). “This work quite elegantly bridges the fields of art and nanotechnology.”

Nature abounds with examples of structural color. The bright colors in butterfly wings don’t come from any pigment molecules but from how the wings are structured, for instance. The scales of chitin (a polysaccharide common to insects) are arranged like roof tiles. Essentially, they form a diffraction grating, except photonic crystals only produce certain colors, or wavelengths, of light while a diffraction grating will produce the entire spectrum, much like a prism 

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#biomimicry, #gaming-culture, #materials-science, #meta-materials, #nanopillars, #nanotechnology, #optics, #painting-with-light, #physics, #science

Researchers demonstrate in-chip water cooling

Image of a metallic device with multiple layers of channels cut into it.

Enlarge / A hierarchy of channels keeps coolant flowing without requiring high pressures.

As desktop processors were first crossing the Gigahertz level, it seemed for a while that there was nowhere to go but up. But clock speed progress eventually ground to a halt, not because of anything to do with the speed itself but rather because of the power requirements and the heat all that power generated. Even with the now-common fans and massive heatsinks, along with some sporadic water cooling, heat remains a limiting factor that often throttles current processors.

Part of the problem with liquid cooling solutions is that they’re limited by having to get the heat out of the chip and into the water in the first place. That has led some researchers to consider running the liquid through the chip itself. Now, some researchers from Switzerland have designed the chip and cooling system as a single unit, with on-chip liquid channels placed next to the hottest parts of the chip. The results are an impressive boost in heat-limited performance.

Feeling the heat

Part of our issue with getting heat out of a chip is that it usually involves multiple connections: from the chip to the chip packaging and the chip packaging to a heat sink. While steps can be made to improve these connections, there’s an inefficiency to them, which adds up to limit the heat we can extract from the chip. This is true for the liquid cooling systems in current use, which use the liquid to replace the metal heat sink. While it might be possible to place the chip directly into a heat-conductive liquid, that liquid has to be an insulator and not undergo any chemical reactions with electronics components—both hurdles that water fails to clear.

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#cooling, #materials-science, #processors, #science

Could “disordered rock salts” bring order to next-gen lithium batteries?

Image of a large crystal of salt.

Enlarge / Ordered rock crystals, courtesy of a salt mine. (credit: Lech Darski)

Better batteries are a critical enabling technology for everything from your gadgets all the way up to the stability of an increasingly renewable grid. But most of the obvious ways of squeezing more capacity into a battery have been tried, and they all run straight into problems. While there may be ways to solve those problems, they’re going to need a lot of work to overcome those hurdles.

Earlier this week, a paper covers a new electrode material that seems to avoid the problems that have plagued other approaches to expanding battery capacity. And it’s a remarkably simple material: a variation on the same structure that’s formed by crystals of table salt. While it’s far from being ready to throw in a battery, the early data definitely indicate it’s worth looking into further.

Lithium density

Lithium-ion batteries, as their name implies, involve shuffling lithium between the cathode and the anode of the battery. The consequence of this is that both of the electrodes will end up needing to store lithium atoms. So most ideas for next-generation batteries involve finding electrode materials that do so more effectively.

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#batteries, #chemistry, #lithium, #materials-science, #science

Solar+battery in one device sets new efficiency standard

Image of a large container near solar panels.

Enlarge / Existing solar+battery solutions involve two separated pieces of hardware. (credit: DOE)

The drop in battery prices is enabling battery integration with renewable systems in two contexts. In one, the battery serves as a short-term power reservoir to smooth over short-term fluctuations in the output of renewable power. In the other, the battery holds the power for when renewable power production stops, as solar power does at night. This works great for off-grid use, but it adds some complications in the form of additional hardware to convert voltages and current.

But there’s actually an additional option, one that merges photovoltaic and battery hardware in a single, unified device that can have extensive storage capacity. The main drawback? The devices have either been unstable or have terrible efficiency. But an international team of researchers has put together a device that’s both stable and has efficiencies competitive with those of silicon panels.

Solar flow batteries

How do you integrate photovoltaic cells and batteries? At its simplest, you make one of the electrodes that pulls power out of the photovoltaic system into the electrode of a battery. Which sounds like a major “well, duh!” But integration is nowhere near that simple. Battery electrodes, after all, have to be compatible with the chemistry of the battery—for lithium-ion batteries, for example, the electrodes end up storing the ions themselves and so have to have a structure that allows that.

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#battery, #chemistry, #flow-battery, #green, #green-energy, #materials-science, #photovoltaics, #renewable-energy, #science

New material releases hydrogen from water at near-perfect efficiency

Image of the setting Sun.

Enlarge (credit: NASA/Dimitri Gerondidakis)

Solar energy is currently dominated by photovoltaic devices, which have ridden massive economies of scale to price dominance. But these devices are not necessarily the best choice in all circumstances. Unless battery technology improves, it’s quite expensive to add significant storage to solar production. And there are types of transportation—long-distance rail, air—where batteries aren’t a great solution. These limitations have made researchers maintain interest in alternate ways of using solar energy.

One alternative option is to use the energy to produce a portable fuel, like a hydrocarbon or hydrogen itself. This is possible to do with the electrons produced by photovoltaic systems, but the added steps can reduce efficiency. However, systems that convert sunlight more directly to fuel have suffered from even worse efficiencies.

But a Japanese group has decided to tackle this efficiency problem. The team started with a material that’s not great—it only absorbs in the UV—but is well understood. And the researchers figured out how to optimize it so that its efficiency at splitting water to release hydrogen runs right up against the theoretical maximum. While it’s not going to be useful on its own, it may point the way toward how to develop better materials.

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#energy, #green, #hydrogen, #materials-science, #renewable-energy, #science, #solar-power

Right-to-repair groups fire shots at medical device manufacturers

Right-to-repair groups fire shots at medical device manufacturers

Enlarge (credit: Buda Mendes | Getty Images)

The website iFixit has long been known for its electronics repair kits and for its very public stance that repair manuals should be accessible to everyone. That’s one of the foundational arguments of the broader right-to-repair movement, which lobbies that regular consumers should be able to repair the products they’ve purchased—everything from smartphones to washing machines to farming equipment—without violating a warranty. Now, in the time of COVID-19, iFixit and a prominent consumer interest group are tackling a more immediate concern: access to repair manuals for medical devices.

The company said this week it’s releasing what it calls the “most comprehensive medical equipment service database in the world.” The collection of thousands of files is supposed to help biomedical engineering technicians—the techs who update or fix medical equipment on site at health care facilities—repair everything from imaging equipment to EKG monitors to ventilators. iFixit founder and CEO Kyle Wiens (who also contributes to WIRED’s Ideas section) called it an “absolutely massive” undertaking for iFixit, a project that took more than two months to coordinate and required help from 200 volunteers.

The rollout of the iFixit database is also coming on the heels of a letter sent to state legislators by Calpirg, the California arm of the US Public Interest Research Group, with more than 300 signatures from hospital repair experts. In the letter, the group calls for loosened restrictions on repairs of medical equipment and more cooperation from makers of medical devices.

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#materials-science, #science

Study: Future astronauts could use their own urine to help build moon bases

Future moon bases could be built with 3D printers that mix materials such as Moon regolith, water, and astronauts’ urine.

Enlarge / Future moon bases could be built with 3D printers that mix materials such as Moon regolith, water, and astronauts’ urine. (credit: ESA/Foster and Partners)

Early last year, NASA announced an ambitious plan to return American astronauts to the Moon and establish a permanent base there, with an eye toward eventually placing astronauts on Mars. The Artemis Moon Program has its share of critics, including many in the US House of Representatives, who appear to prefer a stronger focus on a crewed mission to Mars. As Ars’ Eric Berger reported last August, “NASA stands a very real risk of turning the Artemis Program into a repeat of the Apollo Program—a flags-and-footprints sprint back to the Moon with no follow-through in the form of a lunar base or a sustained presence in deep space.”

But if the Artemis Program’s ambitious objectives survive the appropriations process, materials science will be crucial to its success, particularly when it comes to the materials needed to construct a viable lunar base. Concrete, for instance, requires a substantial amount of added water in order to be usable in situ, and there is a pronounced short supply of water on the moon. In a new paper in the Journal of Cleaner Production, an international team of scientists suggests that astronauts setting up a base on the moon could use the urea in their urine as a plasticizer to create a concrete-like building material out of lunar soil.

There’s certainly a strong argument to be made for using existing materials on the Moon itself to construct a lunar base. NASA estimates that it costs around $10,000 to transport one pound of material into orbit, according to the authors. Past proposals have called for 3D printing with Sorel cement, which requires significant amounts of chemicals and water (consumables), and a rocklike material that would require both water and phosphoric acid as a liquid binder. (The latter might be better suited to constructing a base on Mars.)

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#astronauts, #esa, #lunar-base, #materials-science, #moon-colonization, #physics, #science, #space