#steel

New Shock-Absorbing Material is Strong as Steel and Light as FoamResearchers from John Hopkins University have developed a new shock-absorbing material that is as strong as steel but as light as foam. The material offers more protection from a wide range of impacts, but being lighter could reduce fuel consumption and the environmental impact of vehicles. If applied en masse, this could be a game changer for helmets, body armor, and automobile and aerospace parts.The research team, headed by Sung Hoon Kang, increased the material's ability to withstand impact by using high energy-absorbing liquid crystal elastomers (LCEs), which have been used mainly in actuators and robotics.In their durability tests, it held up against strikes from objects weighing about four to 15 pounds, coming at speeds of up to about 22 miles per hour. The tests were limited to 22 miles per hour due to limits of the testing machines, but the team is confident the padding could safely absorb even greater impacts.They are currently exploring a collaboration with a helmet company to design, fabricate, and test next-generation helmets for athletes and the military.Image: Will Kirk/Johns Hopkins University#NewMaterial #steel #foam #armor #LiquidCrystalElastomers

MIT Chemical Engineers Created New Kind of Plastic That's Twice as Strong as SteelChemical engineers from MIT produced a new material that is tougher than steel and as light as plastic. It can also be easily manufactured in bulk.“We don’t usually think of plastics as being something that you could use to support a building, but with this material, you can enable new things, it has very unusual properties and we’re very excited about that,” says Michael Strano, senior author of the new study.In the research, Strano and his colleagues devised a new polymerization process that permitted them to create a two-dimensional sheet of polyaramide — something that scientists in the past had tried to make for decades and thus concluded wrongly that such a structure was impossible to create. They used melamine as monomer building blocks. Under the right conditions, these monomers grew in two dimensional-sheets and formed disks which make the structure very strong.The MIT researchers proceeded to coat surfaces with films of the new material, which they called 2DPA-1. They found 2DPA-1 to be four to six times harder to be deformed (elastic modulus) than bulletproof glass. It is also twice as hard to break (yield strength) than steel — while having only one-sixth the density of the latter. The material is also impermeable to gases. “This could allow us to create ultrathin coatings that can completely prevent water or gases from getting through. This kind of barrier coating could be used to protect metal in cars and other vehicles, or steel structures,” Strano says.The Center for Enhanced Nanofluidic Transport (CENT) funded this research.Image credit: polymer film courtesy of the researchers; Christine Daniloff, MIT#research #plastic #engineering #MIT #newmaterial #steel

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

World’s First 3D-Printed Steel BridgeLast week, the world’s first 3D-printed steel bridge was unveiled in Amsterdam, the Netherlands.The 40-foot-long (12 meter) bridge was created from 6 tons of stainless steel in just 6 months by four industrial 3D printing robots by Dutch company MX3D. It was created using a 3D printing technique called wire and arc additive manufacturing that combines robotics with welding.In addition to serving as a foot bridge over one of the canals in Amsterdam’s city center, it will also serve as a “living laboratory” as a network of sensors will monitor and analyze its performance as the bridge serves pedestrian traffic. The data collected will enable engineers to measure the bridge’s ‘health’ in real time and understand further how 3D printed steel structures will perform over time.Professor Leroy Gardner of the Department of Civil and Environmental Engineering of Imperial College London said in a statement, “D printing presents tremendous opportunities to the construction industry, enabling far greater freedom in terms of material properties and shapes. This freedom also brings a range of challenges and will require structural engineers to think in new ways.”To unveil the new 3D-printed steel bridge, Queen Máxima of the Netherlands pressed a button that prompted a robot to cut a ribbon hanging across the bridge.Images: MX3D#bridge #3DPrinting #MX3D #steel #civilengineering #welding