#materialscience

World's Thinnest Christmas Tree is Made of One Atom Thick Graphene This Christmas tree brings a whole new meaning to 2D Christmas.Peter Bøggild and colleagues at the Technical University of Denmark cut a 14 cm-long Christmas tree from a single layer of graphene, which is one atom thick (and just one-third of a nanometer thick). The graphene Christmas tree was then transferred in one piece using a rebuilt laminating machine and then examined with terahertz radiation:"Even if you could make a pencil drawing of a Christmas tree and lift it off the paper—which, figuratively, is what we have done—it would be much thicker than one atom. A bacterium is, e.g. 3000 times thicker than the graphene layer we used. That's why I dare call this the world's thinnest Christmas tree. And although the starting point is carbon, just like the graphite in a pencil, graphene is at the same time even more conductive than copper. The "drawing" is made in one perfect layer in one piece, " says Professor Peter Bøggild who lead the team behind the Christmas tree experiment.The display of quality in this production showed how accurate the control of this method was. This is expected to propel the use of technology since graphene is known to be a good conductor of electricity and, given it is a two-dimensional material (it consists of atoms in one cohesive layer that is only one atom thin), it would weigh less and take up less space compared to other electronics we know today.

Scientists Measured the Mechanical Forces Applied to Break a Single Chemical BondWouldn't it be nice if we could measure the mechanical forces applied in atoms at the moment of breakage? Thanks to today's technology, it has already been made possible. Using a high-resolution atomic force microscope (AFM), researchers from Princeton University, the University of Texas-Austin, and ExxonMobil recorded the breaking of a single chemical bond between a carbon atom (which was from a carbon monoxide molecule) and an iron atom (from iron phthalocyanine). The findings could have applications for biochemistry, materials science, and energy technologies. The said findings were reported in a paper recently published in Nature Communications. Now, scientists know the amount of force needed to break a single chemical bond. Learn more about this study over at Princeton University. (Image Credit: Pengcheng Chen et al.) #MolecularBreakup #Chemistry #Atom #Molecule #MaterialScience

Chainmail-Inspired 3D Printed Material Transforms From Flexible to Rigid on CommandIn the 2005 movie Batman Begins, Batman's cape is flexible but can be made into a rigid glider. Now, engineers at Caltech and JPL have developed a material that can transform from flexible to rigid on command."We wanted to make materials that can change stiffness on command," said Chiara Daraio of Caltech, "We'd like to create a fabric that goes from soft and foldable to rigid and load-bearing in a controllable way."A material that can transform from flexible to rigid isn't as unusual as one would think. In fact, Daraio added, many people have something that works like that in their pantries: a bag of vacuum-sealed coffee. When coffee grounds are packed, they are solid as the individual particles are jammed against each other. But when the package is opened, then the coffee grounds are no longer jammed and can pour out as if they were liquid.To create a new material that has both flexible and rigid properties, Daraio and colleagues designed various configurations of linked particles, including linking rings, linking cubes and finally linking octahedrons (which look like two pyramids connected at the base).The linked octahedron material is then 3D printed out of plastic polymers and even metal, resulting in a chainmail-like fabric."Granular materials are a beautiful example of complex systems, where simple interactions at a grain scale can lead to complex behavior structurally. In this chain mail application, the ability to carry tensile loads at the grain scale is game changer. It's like having a string that can carry compressive loads. The ability to simulate such complex behavior opens the door to extraordinary structural design and performance," said José E. Andrade of Caltech.When it is compressed, the chainmail material is able to support more than 50 times the fabric's weight."These fabrics have potential applications in smart wearable equipment: when unjammed, they are lightweight, compliant, and comfortable to wear; after the jamming transition, they become a supportive and protective layer on the wearer's body," said the study's co-lead author Yifan Wang now at Nanyang University.Images: Caltech and Nanyang University#chainmail #materialscience #engineering #octahedron #3Dprinting #Caltech #JPL

Food Scraps Recycled Into Materials Stronger Than Concrete (But Strangely Remained Edible)The option for food waste is quite limited - either throw it away or compost it - but there may soon be a third option: make it into a new and robust construction material.Researchers from the Institute of Industrial Science at The University of Tokyo first turned fruit and vegetable scraps such as seaweed, cabbage leaves as well as orange, onion, pumpkin, and banana peels into powder. Then, they mixed the powder with some water, poured the resulting mixture into a mold and pressed it at high temperature.When they tested the newly molded material, the researchers discovered that they were quite strong. "With the exception of the specimen derived from pumpkin, all of the materials exceeded our bending strength target," said Kota Machida in a statement, "We also found that Chinese cabbage leaves, which produced a material over three times stronger than concrete, could be mixed with the weaker pumpkin-based material to provide effective reinforcement."Surprisingly, the materials remained edible. They were also more resistant to rotting, fungus and insect infestations and didn't change in appearance or taste after being exposed to air for up to four months.#food #recycling #concrete #ConstructionMaterial #MaterialScience

Microbially Produced Artificial Amyloid-Silk Hybrid Protein Fiber is Stronger Than Steel and KevlarSpider silk is lighter than a feather but stronger than steel. It's thinner than a human hair but can handle weight hundreds of times its own. Its tensile strength (1.1 gigapascal) beats that of steel (05 gigapascal), and its toughness is comparable to that of Kevlar.But even nature can't compete with synthetic biology: a new lab-created artificial silk is even stronger. The new material is called polymeric amyloid fiber. It is produced by genetically modified bacteria in the lab of Fuzhong Zhang of Washington University in St. Louis.From WUSL The Source Newsroom:To solve this problem, the team redesigned the silk sequence by introducing amyloid sequences that have high tendency to form β-nanocrystals. They created different polymeric amyloid proteins using three well-studied amyloid sequences as representatives. The resulting proteins had less repetitive amino acid sequences than spider silk, making them easier to be produced by engineered bacteria. Ultimately, the bacteria produced a hybrid polymeric amyloid protein with 128 repeating units....The longer the protein, the stronger and tougher the resulting fiber. The 128-repeat proteins resulted in a fiber with gigapascal strength (a measure of how much force is needed to break a fiber of fixed diameter), which is stronger than common steel. The fibers’ toughness (a measure of how much energy is needed to break a fiber) is higher than Kevlar and all previous recombinant silk fibers. Its strength and toughness are even higher than some reported natural spider silk fibers.#spider #spidersilk #artificialspidersilk #steel #Kevlar #polymericamyloidfiber #protein #RecombinantProtein #amyloid #materialscience

New 3D Tensegrity Metamaterial is Ultra Lightweight and Crush-ResistantCatastrophic collapse of materials usually involves a chain reaction of small, localized damages or deformities - think of a crack in the windshield of a car that started with a small chip in the glass.But what if you could avoid local deformity?Engineers at University of California, Irvine and the Georgia Institute of Technology have created a new metamaterial using tensegrity to avoid localized deformities to prevent failure.They start with direct laser writing technique to generate elementary cells sized about 10 to 20 micron. These were built into 8-unit supercells that are assembled with others to make a continuous structure. Upon testing, the new metamaterial feature 25-fold improvement in deformability and orders-of-magnitude increase in energy absorption.

Scientists Can Grow Super Strong 'Metallic Wood'After three years of trying, the engineers at the University of Pennsylvania's School of Engineering and Applied Science have succeeded in creating a new type of material they've dubbed 'metallic wood.'The new material, a lattice of nanoscale nickel struts, has high strength-to-density ratio akin to wood from trees which are strong enough to grow hundreds of feet tall but light enough to float on water.In the image above, a strip of metallic wood about 1 inch long and one-third inch wide (2.5 cm by 0.8 cm) is thinner than household aluminum foil but is capable of supporting 50 times its own weight without buckling. If the weight was suspended from it, the same strip could support more than 6 lb (2.7 lg) without breaking.The key to the metallic wood's success is the precise spacing of the nanolattic and avoiding cracks when the material is being manufactured."Our new manufacturing approach allows us to make porous metals that are three times stronger than previous porous metals at similar relative density and 1,000 times larger than other nanolattices," said professor James Pikul. "We plan to use these materials to make a number of previously impossible devices, which we are already using as membranes to separate biomaterials in cancer diagnostics, protective coatings, and flexible sensors."

Lightweight LEGO-Like 3D-Printed Alternative to Reinforced Concrete BeamsReinforced concrete beams, a staple in civil engineering, are strong ... but they are also very, very heavy.Thanks to 3D printing, a team of researchers at the Polytechnic University of Valencia (UPV) in Spain has developed a lightweight alternative. The 3D printed plastic pieces are snapped together onsite, just like LEGO pieces. Then the structure is concreted into place, with no metal reinforcement required.The resulting beam is just as strong as reinforced concrete beam, but weighs up to 80% less.How did the researchers achieve the required rigidity from plastic? By studying human bones:"It is an alveolar structure, which makes it possible to decrease the amount of plastic used – and therefore its weight – while maintaining structural rigidity," said Jose Ramon Albiol of the Higher Technical School of Construction Engineering of the UPV, "This is what we have transferred to these revolutionary beams, specifically to their profiles. It is a very intelligent natural system and its reproduction in these beams awards them, with the low structural weight, very high mechanical capabilities."via AlphaGalileo#3DPrinting #concrete #CivilEngineering #LEGO #plastic #materialscience