News from the NNI Community - Research Advances Funded by Agencies Participating in the NNI

Twisted bilayer graphene, made of two sheets of graphene twisted to a specific "magic" angle, has been shown to have superconductivity, meaning that it can conduct electricity with very little resistance. But using this approach to make devices remains challenging because of the low yield of fabricating twisted bilayer graphene. Now, researchers at the University of Pennsylvania have shown how patterned, periodic deformations of a single layer of graphene transforms it into a material with electronic properties previously seen in twisted graphene bilayers. Through a better understanding of how unique properties occur when single sheets of graphene are subjected to periodic strain, this work could create quantum devices, such as orbital magnets and superconductors, in the future. 

Researchers at Rice University have created a potentially disruptive technology for the ultraviolet optics market. By precisely etching hundreds of tiny nanotriangles on the surface of a microscopic film of zinc oxide, nanophotonics pioneer Naomi Halas and colleagues have created a "metalens" that transforms incoming long-wave ultraviolet A radiation into a focused output of vacuum ultraviolet radiation. This type of radiation is used in semiconductor manufacturing, photochemistry, and materials science and has historically been costly to work with, in part because it is absorbed by almost all types of glass used to make conventional lenses.

Researchers at the U.S. Department of Energy’s Sandia National Laboratories have developed a nanocomposite coating that could be used in many applications, such as shielding in the form of mechanical barriers, body armor, and space debris shields. The coating is composed of thin layers of carbon black interspersed between slightly thicker layers of silica, and it looks like the layering of a seashell, each layer helping the next to contain and mitigate shock.

Researchers at the University of Alabama at Birmingham have developed a novel therapy that improves obesity and Type 2 diabetes conditions of mice that were fed a high-fat diet. The therapy acts through sustained release of nitric oxide, a gas that relaxes the inner muscles of blood vessels. The researchers used a nanomatrix gel composed of peptide-based molecules that self-assemble into cylindrical micelle nanofibers. The nanomatrix gel can release a burst of nitric oxide in the first 24 hours, followed by sustained nitric oxide release for four weeks. At the end of 12 weeks, the nitric oxide-mice had gained 17% less body weight, compared to controls, and that weight difference was due mainly to decreased fat.

Researchers have routinely studied DNA and protein molecules by turning them into regularly packed crystals that can be examined with an X-ray beam or radio waves. However, these techniques cannot be applied to RNA molecules with nearly the same effectiveness, because their molecular composition and structural flexibility prevent them from easily forming crystals. Now, researchers from the Wyss Institute for Biologically Inspired Engineering at Harvard University and Harvard Medical School have reported a new approach to the structural investigation of RNA molecules. This approach uses an RNA nanotechnological technique that allows multiple identical RNA molecules to be assembled into a highly organized structure. 

Researchers from Rice University, Arizona State University, and the U.S. Department of Energy’s Pacific Northwest National Laboratory have developed a high-performance catalyst that can, with near 100% efficiency, pull ammonia from low levels of nitrates that are widespread in industrial wastewater and polluted groundwater. The researchers showed that the catalyst, which was made by dispersing ruthenium atoms into a copper nanowire matrix, converts nitrate levels of 2,000 parts per million into ammonia, followed by an efficient gas stripping process for ammonia product collection.

Researchers from Michigan State University and the Max Planck Institute of Molecular Plant Physiology in Germany have repurposed bacterial microcompartments (each about 40 nanometers in diameter) and programmed them to produce valuable chemicals from inexpensive starting ingredients. The researchers engineered the microcompartments to turn the simple and inexpensive compounds formate and acetate into pyruvate, bringing enzymes and these compounds together in the same, smaller space, rather than having them spread out throughout a bacterial cell.

Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and three German universities (Technische Universitat Bergakademie Freiberg, Universitat Hamburg, and Technische Universitat Munchen) have found a way to track electrons along their round trip from molecules to nanoparticles in materials that convert sunlight into electricity or fuels. The scientists found that a common nanoparticle material, zinc oxide, first stalls the electrons for a while and then lets the electrons move along the surface of the nanoparticles. This makes it likely that the charges can get lost or can damage the nanoparticle material. The ability to reveal these bottlenecks for electron travel will help researchers design better materials for turning sunlight into other forms of energy. 

Researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, the University of California, Berkeley, Cornell University, and Rutgers University have discovered layered two-dimensional (2D) materials that can host unique magnetic features and remain stable at room temperature. Atomic-scale images of the material reveal the precise chemical and structural characteristics that are responsible for these features and their stability.

Researchers from the University of Nebraska-Lincoln, Asylum Research, the University of Strasbourg in France, the University of Luxemburg, and East China Normal University in Shanghai have demonstrated that a 2D material, called molybdenum disulfide, has a long-theorized property that could help computers, phones, and other microelectronics save both power and their electrical states, even after being turned off. In the wake of this study, molybdenum disulfide now joins a handful of materials that have high-yet-controllable conductivity and easily switchable polarization.