It's historically been tough and slow-going to 3D print objects made from multiple materials. Now, Harvard researchers developed an ingenious nozzle that enables the 3D printer to spew out eight different materials at the resolution of a human hair. To demonstrate the system, they printed fantastic flexible origami structures and even a "soft" robotic millipede from a variety of epoxy and silicone elastomer inks. Mark A. Skylar-Scott, Jochen Mueller, and their colleagues from Harvard's Wyss Institute for Biologically Inspired Engineering presented their work in the scientific journal Nature: "Voxelated soft matter via multimaterial multinozzle 3D printing"
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The US Air Force Research Laboratory (AFRL) has developed a new form of liquid metal with very strange conductive properties. Usually, when a flexible, conductive material is stressed or stretched, its electrical conductivity drops and resistance increases when it's stress or stretched. Just the opposite, Air Force's novel "Polymerized Liquid Metal Networks... can be strained up to 700%, autonomously respond to that strain to keep the resistance between those two states virtually the same, and still return to their original state." The researchers published their results in the scientific journal Advanced Materials. From the Air Force:
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It is all due to the self-organized nanostructure within the material that performs these responses automatically.
“This response to stretching is the exact opposite of what you would expect,” said Dr. Christopher Tabor, AFRL lead research scientist on the project. “Typically a material will increase in resistance as it is stretched simply because the current has to pass through more material. Experimenting with these liquid metal systems and seeing the opposite response was completely unexpected and frankly unbelievable until we understood what was going on.”
Wires maintaining their properties under these different kinds of mechanical conditions have many applications, such as next-generation wearable electronics. For instance, the material could be integrated into a long-sleeve garment and used for transferring power through the shirt and across the body in a way that bending an elbow or rotating a shoulder won’t change the power transferred.
The Wood Database presents the hardest woods.
8. Black Ironwood
7. African Blackwood
2. Lignum Vitae
You'll have to click through to find out what number 1 is! All perfect names for weaponry materials in a wood-themed RPG. And here's the softest woods, which is only lightly spoiled by pointing out that "nothing else comes close" to Balsa except Quipo, which is of similar softness to Balsa and "virtually unobtainable". Read the rest
Alice Potts engages in what she calls "human body design," creating bioplastics by soaking materials in body fluids to embed them with crystals. Read the rest
Researchers demonstrated a new process that makes wood stronger than steel. According to the University of Maryland mechanical engineers, their novel process could lead to a greener alternative to metal in automobiles, airplanes, or buildings. “This could be a competitor to steel or even titanium alloys, it is so strong and durable," says researcher Liangbing Hu. "It’s also comparable to carbon fiber, but much less expensive.” From the University of Maryland:
The team’s process begins by removing the wood’s lignin, the part of the wood that makes it both rigid and brown in color. Then it is compressed under mild heat, at about 150 F. This causes the cellulose fibers to become very tightly packed. Any defects like holes or knots are crushed together. The treatment process was extended a little further with a coat of paint.
The scientists found that the wood’s fibers are pressed together so tightly that they can form strong hydrogen bonds, like a crowd of people who can’t budge – who are also holding hands. The compression makes the wood five times thinner than its original size.
The team tested their new wood material and natural wood by shooting bullet-like projectiles at it. The projectile blew straight through the natural wood. The fully treated wood stopped the projectile partway through.
More: "Crushed wood is stronger than steel" (Nature)
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This is NASA's new "space fabric" in development at the Jet Propulsion Laboratory. Read the rest
Chinese engineer Song Youzhou has been trying to get traction for his straddling bus, a huge elevated bus that goes over, rather than through, traffic, since 2010. Read the rest
Scientists at the University of Maryland, College Park, have developed see-through wood by removing the material that gives wood its yellowish color and then injecting the wood with epoxy to strengthen it.
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The "invisible" wood -- as Dr. Liangbing Hu of the University's Department of Material Science and Engineering describes it -- is sturdier than traditional wood, and can be used in place of less environmentally friendly materials, such as plastics.
A group at Saudi Arabia's King Abdulla University of Science and Technology have developed a new carbon-nanotube-based material that absorbs 98 to 99 percent of light between 400 and 1,400nm, from all angles, making even blacker than Rice University's 2008 none-more-black, Boston and Duke's 2008 none-more-black and Leiden University's 2009 none-more-black. That's pretty fucking black. Read the rest
Microlattice is "a lattice of interconnected hollow tubes with a wall thickness of 100 nanometers, 1,000 times thinner than a human hair." It's made from nickel and is 99.99% air. As a result, it's very light. Here's a video that demonstrates its properties and discusses its potential use in structural reinforcement and shock absorption.
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MIT researchers and Google-owned Boston Dynamics developed a new wax-and-foam material that can shift between hard and soft states as a basis for future "squishy robots." Read the rest
The spacesuit that Neil Armstrong wore when he stepped onto the moon was constructed by a bra manufacturer in Dover, Delaware. Smithsonian magazine tells the history of the Apollo suit:
For the suit’s creator, the International Latex Corporation in Dover, Delaware, the toughest challenge was to contain the pressure necessary to support life (about 3.75 pounds per square inch of pure oxygen), while maintaining enough flexibility to afford freedom of motion. A division of the company that manufactured Playtex bras and girdles, ILC had engineers who understood a thing or two about rubber garments. They invented a bellowslike joint called a convolute out of neoprene reinforced with nylon tricot that allowed an astronaut to bend at the shoulders, elbows, knees, hips and ankles with relatively little effort. Steel aircraft cables were used throughout the suit to absorb tension forces and help maintain its shape under pressure.
"Neil Armstrong’s Spacesuit Was Made by a Bra Manufacturer" Read the rest
The iceberg wasn't the only thing that took down the Titanic, explains Yale University materials scientist Anissa Ramirez. Instead, cold temperatures in the icy North Atlantic changed the behavior of the materials that made up the boat — changes that reduced the ocean liner's ability to withstand a head-on iceberg collision.
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This morning, Marketplace Tech Report had a story on a new cellulose-based building material that could be made by genetically engineered bacteria — altered versions of the bacteria that naturally make stuff like kombucha. This tech sounds like it's got a long way to go from laboratory to the real world, but if they can perfect the process and make it large enough quantities, what you'd end up with a strong, inexpensive goop that could be used to build everything from medical dressings, to digital paper, to spaceships. Yes, you could theoretically use this stuff to make rocket casings, according to R. Malcolm Brown, Jr., a professor of cell biology at UT Austin. And if you can build a rocket from this stuff, you could also break the same material back down into an edible, high-fiber foodstuff. Read the rest
It's been a good week for pedantry. In a guest blog post at Scientific American, Kyle Hill discusses the durability of spaceship windows — both in the real world, and in Joss Whedon's movie Serenity. Spaceship windows have to be incredibly tough, because even tiny chips of paint become dangerous projectiles in space. But how would they stand up to frontal attack by a spear? Physics has the answers. Read the rest
Stewart Brand sums up Susan Freinkel's Long Now talk: "What Common Objects Used to Be Made Of," a history of the world before plastic:
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“Bakelite was invented in 1907 to replace the beetle excretion called shellac (“It took 16,000 beetles six months to make a pound of shellac.”), and was first used to insulate eletrical wiring. Soon there were sturdy Bakelite radios, telephones, ashtrays, and a thousand other things. The technology democratized consumption, because mass production made former luxury items cheap and attractive. The 1920s and ‘30s were a golden age of plastic innovation, with companies like Dow Chemical, DuPont, and I. G. Farben creating hundreds of new varieties of plastic for thrilled consumers. Cellophane became a cult. Nylons became a cult. A plastics trade show in 1946 had 87,000 members of the public lining up to view the wonders. New fabrics came along—Orlon and Dacron—as colorful as the deluge of plastic toys—Barbie, the Frisbee, Hula hoops, and Silly Putty.
“Looking for new markets, the marketers discovered disposability—disposable cups for drink vending machines, disposable diapers (“Said to be responsible for the baby boom“), Bic lighters, soda bottles, medical syringes, and the infinite market of packaging. Americans consume 300 pounds of plastic a year. The variety of plastics we use are a problem for recycling, because they have to be sorted by hand. They all biodegrade eventually, but at varying rates. New bio-based polymers like “corn plastic” and “plant bottles” have less of a carbon footprint, but they biodegrade poorly. Meanwhile, thanks to the efficiencies of fracking, the price of natural gas feedstock is plummeting, and so is the price of plastic manufacture.
A creative agency called Murmure is kitting out its employees with concrete business cards that come with their own miniature shipping palettes. There's a scene in a William Gibson novel (I could swear it was Idoru, but I can't find it) where a Hollywood studio exec passes out business-cards screened on wafer-thin slices of marble, each in its own velveteen slipcase. These (which come with their own little paper boxes) are a nice second, though not nearly so keen as those fictional bad boys.
Concrete Business Cards
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