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A D V A N C E D M A T E R I A L S & P R O C E S S E S | F E B R U A R Y / M A R C H 2 0 1 8 1 5 CLIMATE CLOTHING COMFORTS WEARERS Scientists at Stanford University, Calif., invented a reversible fabric that can either warm or cool a wearer, de- pending on which side faces out. The layered fabric can increase a person’s range of comfortable temperatures by more than 10°F, though researchers suspect additional tweaks could more than double that. Because a building’s climate control energy can be reduced by more than 10% for every 2°F that a thermostat is turned down in cold weather—or turned up in warm weath- er—the new material could lead to sub- stantial energy savings. Researchers initially created an opaque, breathable, cooling polyeth- ylene that shuttles infrared radiation away from the body, which keeps arti- ficial skin almost 4°F cooler than cot- ton in laboratory tests. Then they sand- wiched a carbon coating and a cop- per coating between two layers of the polyethylene. When the material is worn with the copper lay- er farthest away from the body, the copper traps heat between the polyethylene and the skin, warming the wearer. When the fab- ric is flipped, and the carbon coating is far- thest from the body, the carbon ferries the heat out, cooling the wearer. Researchers are working to in- corporate the material into a fiber-wo- ven structure so it is stronger, stretch- ier, and more comfortable, and they have already begun testing to ensure that the fabric is machine washable. stanford.edu . GRAPHENE GOES BULLETPROOF Researchers at The City Universi- ty of New York (CUNY) developed a pro- cess to layer sheets of graphene into a new material called diamene, a flexible film that temporarily becomes harder than diamond and impenetrable upon impact at room temperature. The team first used computer simulations to model the pressurization of two layers of graphene aligned in different con- figurations, then used an atomic force microscope to apply localized pres- sure to actual two-layer graphene on silicon carbide substrates. Experimen- tal results agree perfectly with initial calculations. “This is the thinnest film with the stiffness and hardness of diamond ever created,” says Elisa Riedo, phys- ics professor. “Previously, when we tested graphite or a single atomic lay- er of graphene, we would apply pres- sure and feel a very soft film. But when the graphite film was exactly two lay- ers thick, all of a sudden we realized that the material under pressure was becoming extremely hard and as stiff, or stiffer, than bulk diamond.” Both theory and experiments confirm that the transition does not occur for more than two layers or for a single layer of graphene. The team also found that the moment of conversion results in a sud- den reduction of electric current, which means diamene could have interesting electronic and spintronic properties as well. cuny.edu . NANOTECHNOLOGY BRIEF The University of Washington, Seattle, launched the Institute for Nano-Engineered Systems to advance nanotech- nology research and engage industry partners in new projects. Headquartered in the new $87.8-million nano-engi- neering and sciences building, the institute will explore disciplines from energy and materials science to computation and medicine. washington.edu . By applying pressure at the nanoscale to two layers of graphene, researchers trans- formed the honeycombed graphene into a diamond-like material at room tem- perature. Courtesy of Ella Maru Studio. Two layers of material with different abilities to release heat energy are stacked together and sandwiched be- tween layers of polyethylene. Courtesy of Yi Cui Group.