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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Microfluidic systems that move and mix tiny amounts of liquids are used in laboratories for biotechnology, chemistry, and even the development of inkjet technology. Frequently, microfluidic devices are integrated into a single "lab on a chip" but fabricating such systems can be costly and time-consuming. Now, MIT researchers are using customized LEGO bricks to make a modular microfluidics platform. Their prototype system "could be used to manipulate biological fluids and perform tasks such as sorting cells, filtering fluids, and encapsulating molecules in individual droplets." From MIT:
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To demonstrate modularity, (mechanical engineering grad student Crystal) Owens built a prototype onto a standard LEGO baseplate consisting of several bricks, each designed to perform a different operation as fluid is pumped through. In addition to making the fluid mixer and droplet generator, she also outfitted a LEGO brick with a light sensor, precisely positioning the sensor to measure light as fluid passed through a channel at the same location.
Owens says the hardest part of the project was figuring out how to connect the bricks together, without fluid leaking out. While LEGO bricks are designed to snap securely in place, there is nevertheless a small gap between bricks, measuring between 100 and 500 microns. To seal this gap, Owens fabricated a small O-ring around each inlet and outlet in a brick.
“The O-ring fits into a small circle milled into the brick surface. It’s designed to stick out a certain amount, so when another brick is placed beside it, it compresses and creates a reliable fluid seal between the bricks.
YouTuber Latheman demonstrates a nicely-designed V2 Stirling engine powered by two spirit lamps. Impressively smooth action on this beauty! Read the rest
University of Michigan mechanical engineering students have built "the world's largest hand-solvable, stationary" Rubik's Cube. Fashioned primarily from aluminum, it weighs 1,500 pounds but can be manipulated by one person. The puzzle is available for solving in the campus's mechanical engineering building. From Michigan Engineering:
They realized they couldn’t simply scale up the approach a handheld cube relies on because the friction would be too great. So to keep friction minimal, they devised a setup that utilizes rollers and transfer bearings.
“This is a truly amazing and unique kinematic mechanism that functions as a Rubik's cube,” said Noel Perkins, the Donald T. Greenwood Collegiate Professor of Mechanical Engineering and advisor to the students.
“There is no other human-manipulable cube like this, to the best of our knowledge. That said, it is not technically the largest cube. We're aware of a larger cube that requires the user to literally roll it on the ground to solve and rotate the faces. None of that is required by our stationary design. So to be very precise, it is the world's largest stationary, human manipulable Rubik's cube.”
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Update: Whoops, David got there first!
In a new paper published in the Proceedings of the Royal Society, researchers from UC Berkeley reveal that shoelace knots do not gradualy come loose, as was previously supposed -- rather, they fail catastrophically and suddenly, thanks to strange and surprising stresses that they must endure.
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Daniel de Bruin built a homemade thrill ride that looks a bit like if The Zipper merged with a camera jib on steroids. The video says the machine reacts to the rider's biometrics, but it doesn't really show how a rider's heart rate changes ride speed. Read the rest
Is this the worst mechanical horse of all time? Chinese farmer Su Daocheng built it to plow his fields and also says he built a homemade helicopter. Probably best to decline rides in both vehicles. At least the head looks nice. He also makes cool mechanical sculptures in his spare time, like this: Read the rest
Retired naval mechanic José Manuel Hermo Barreiro makes incredibly intricate models of engines like the V-12. (via Devour) Read the rest