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Electricity generated from human walking and vehicles on the road can power road lights and signals.
Category: materials – Page 182
As hard as diamond and as flexible as plastic, highly sought-after diamond nanothreads would be poised to revolutionize our world—if they weren’t so difficult to make.
Recently, a team of scientists led by Carnegie’s Samuel Dunning and Timothy Strobel developed an original technique that predicts and guides the ordered creation of strong, yet flexible, diamond nanothreads, surmounting several existing challenges. The innovation will make it easier for scientists to synthesize the nanothreads—an important step toward applying the material to practical problems in the future. The work was recently published in the Journal of the American Chemical Society.
Diamond nanothreads are ultra-thin, one-dimensional carbon chains, tens of thousands of times thinner than a human hair. They are often created by compressing smaller carbon-based rings together to form the same type of bond that makes diamonds the hardest mineral on our planet.
Researchers with the University of Chicago Pritzker School of Molecular Engineering have shown for the first time how to design the basic elements needed for logic operations using a kind of material called a liquid crystal—paving the way for a completely novel way of performing computations.
The results, published Feb. 23 in Science Advances, are not likely to become transistors or computers right away, but the technique could point the way towards devices with new functions in sensing, computing and robotics.
“We showed you can create the elementary building blocks of a circuit—gates, amplifiers, and conductors—which means you should be able to assemble them into arrangements capable of performing more complex operations,” said Juan de Pablo, the Liew Family Professor in Molecular Engineering and senior scientist at Argonne National Laboratory, and the senior corresponding author on the paper. “It’s a really exciting step for the field of active materials.”
Imagine dropping a tennis ball onto a bedroom mattress. The tennis ball will bend the mattress a bit, but not permanently—pick the ball back up, and the mattress returns to its original position and strength. Scientists call this an elastic state.
On the other hand, if you drop something heavy—like a refrigerator—the force pushes the mattress into what scientists call a plastic state. The plastic state, in this sense, is not the same as the plastic milk jug in your refrigerator, but rather a permanent rearrangement of the atomic structure of a material. When you remove the refrigerator, the mattress will be compressed and, well, uncomfortable, to say the least.
But a material’s elastic-plastic shift concerns more than mattress comfort. Understanding what happens to a material at the atomic level when it transitions from elastic to plastic under high pressures could allow scientists to design stronger materials for spacecraft and nuclear fusion experiments.
Scientists from Nanyang Technological University, Singapore (NTU Singapore), have developed a fast and low-cost imaging method that can analyze the structure of 3D-printed metal parts and offer insights into the quality of the material.
Most 3D-printed metal alloys consist of a myriad of microscopic crystals, which differ in shape, size, and atomic lattice orientation. By mapping out this information, scientists and engineers can infer the alloy’s properties, such as strength and toughness. This is similar to looking at wood grain, where wood is strongest when the grain is continuous in the same direction.
This new made-in-NTU technology could benefit, for example, the aerospace sector, where low-cost, rapid assessment of mission critical parts—turbine, fan blades and other components—could be a gamechanger for the maintenance, repair and overhaul industry.
The material could replace rare metals and lead to more economical production of carbon-neutral fuels.
Scientists identify a long-sought magnetic state predicted nearly 60 years ago.
Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have discovered a long-predicted magnetic state of matter called an “antiferromagnetic excitonic insulator.”
“Broadly speaking, this is a novel type of magnet,” said Brookhaven Lab physicist Mark Dean, senior author on a paper describing the research just published in Nature Communications. “Since magnetic materials lie at the heart of much of the technology around us, new types of magnets are both fundamentally fascinating and promising for future applications.”
Bend Your Vase Mode Prints
Posted in materials, transportation
[Stefan] from CNCKitchen wanted to make some bendy tubes for a window-mountable ball run, and rather than coming up with some bent tube models, it seemed there might be a different way to achieve the desired outcome. Starting with a simple tube model designed to be quickly printed in vase mode, he wrote a Python script which read in the G-Code, and modified it allow it to be bent along a spline path.
Vase mode works by slowly ramping up the Z-axis as the extruder follows the object outline, but the slicing process is still essentially the same, with the object sliced in a plane parallel to the bed. Whilst this non-planar method moves the Z-axis in sync with the horizontal motion (although currently limited to only one plane of distortion, which simplifies the maths a bit) it is we guess still technically a planar solution, but just an inclined plane. But we digress, non-planar in this context merely means not parallel to the bed, and we’ll roll with that.
[Stefan] explains that there are quite a few difficulties with this approach. The first issue is that on the inside of the bend, the material flow rate needed to be scaled back to compensate. But the main problem stems from the design of the extruder itself. Intended for operating parallel to the bed, there are often a few structures in the way of operating at an angle, such as fan mounts, and the hotend itself. By selecting an appropriate machine and tweaking it a bit, [Stefan] managed to get it to work at angles up to 30 degrees off the horizontal plane. One annoyance was that the stock nozzle shape of his E3D Volcano hotend didn’t lend itself to operating at such an inclination, so he needed to mount an older V6-style tip with an adapter. After a lot of tuning and fails, it did work and the final goal was achieved! If you want to try this for yourselves, the code for this can be found on the project GitHub.
The unsung star of Jurassic Park was a mosquito frozen in amber. While you can’t really extract blood from specimens like that, you could be transported back in time if you looked at a specimen of fossilized tree sap and found a 110 million-year-old lizard staring back at you.
Creatures get trapped in amber all the time, but most prehistoric finds are insects. Amber is a great material for preserving arthropods because of their already tough shells that will hold on even if the insides disintegrate. But what about a lizard? Retinosaurus hkamentiensis is a new extinct species of lizard that was unexpectedly found trapped in Burmese amber. No one expected an entire reptile to be preserved so well, from its scaly skin down to its skeleton.
What are now the empty eyes of Retinosaurus may have once seen dinosaurs or giant ferns or dragonflies the size of your head. It was determined to be a juvenile that ran into a sticky situation when it ran into a glob of tree amber that it couldn’t escape. It was so well preserved that paleontologist Andrej Čerňanský of Comenius University and his team, who recently published a study in Scientific Reports, approached the prehistoric lizard almost as if it were alive.