[Image above] Credit: NIST
NANOMATERIALS
Graphene is strong, but is it tough?
Scientists at Lawrence Berkeley National Lab have developed the first known statistical theory for the toughness of polycrystalline graphene, which is made with chemical vapor deposition, and found that it is indeed strong (albeit not quite as strong as pristine monocrystalline graphene), but more importantly, its toughness—or resistance to fracture—is quite low.
Molybdenum disulfide engineered into ideal memristors
Researchers at Michigan Technological University have made an ideal memristor based on molybdenum disulfide nanosheets. The material’s success comes down to engineering atomic structures. The research team started with bulk molybdenum disulfide, then manipulated the atomic structural arrangements, referred to as different crystal phases.
Scientists guide gold nanoparticles to form “diamond” superlattices
Using bundled strands of DNA, scientists at the Brookhaven National Lab have devised a way to trap and arrange nanoparticles in a way that mimics the crystalline structure of diamond. The arrangement may open a path to new materials that take advantage of the optical and mechanical properties of this crystalline structure for applications such as optical transistors, color-changing materials, and lightweight yet tough materials.
ENERGY
Claims for solar cell efficiency put to test at NREL
The sheet of paper taped to the door of Keith Emery’s office tells the story. On the paper is a simple fever chart showing the improvements made in increasing the efficiency of two dozen types of solar cells. More than anyone at the Energy Department’s National Renewable Energy Laboratory, Emery has seen the lines on that chart move ever higher.
Interaction between perovskites and quantum dots could improve LED and solar
Researchers from James I University and University of Valencia have quantified the “exciplex state” resulting from the coupling of halide perovskites and colloidal quantum dots. Both known separately for their optoelectronic properties, when brought together these materials yield much longer wavelengths than can be achieved by either material alone, plus easy tuning properties.
Room-temperature lithium metal battery closer to reality
A Cornell team proposed in a recent study that by designing nanostructured membranes with pore dimensions below a critical value, it is possible to stop growth of dendrites in lithium batteries at room temperature. The idea was to take advantage of “hairy” nanoparticles, created by grafting polyethylene oxide onto silica to form nanoscale organic hybrid materials to create nanoporous membranes.
OTHER RESEARCH
Warwick engineers develop micro-SLA 3-D printing for piezoceramics
Researchers from the University of Warwick in the U.K. have now developed a whole new microstereolithography 3-D printing technique that can be used to create piezoceramic objects. Just millimeters in size, these objects form the basis of a wide range of electronic devices. Most importantly, their technique doesn’t suffer from the limitations that affect existing piezoceramic production techniques.
Turning 3-D grain maps into a finite element mesh
Modern beamlines at synchrotron facilities allow observation of structural materials’ three dimensions. By adding diffraction information, it is possible to retrieve the 3-D spatial arrangement of crystallographic grains composing polycrystalline metallic specimens. Dedicated meshing routines are developed to use the real 3-D grain microstructure for finite element calculations.
Flat, ultralight lens could change how cameras are designed
Researchers have always thought that flat, ultrathin optical lenses for cameras or other devices were impossible because of the way all the colors of light must bend through them. But University of Utah researchers developed a new method of creating optics that are flat and thin yet can still perform the function of bending light to a single point, the basic step in producing an image.
Scientists bridge different materials by design
Scientists at the University of Liverpool have shown that it is possible to design and construct interfaces between materials with different structures by making a bridge between them. The design and formation of an atomic-scale bridge will lead to new and improved physical properties, opening the path to new information technology and energy science applications amongst a myriad of science and engineering possibilities.
Making sense of metallic glass
A team of Carnegie Institution for Science researchers is trying to figure out the rules that govern metallic glass’s creation by looking at metallic glasses under extreme pressures. The team probed glass made from alloys of the metal cerium under pressure. Their goal was to look for fundamental rules correlating the structure and properties of metallic glasses that could aid their further discovery and synthesis going forward.
Germanium-based photonics offer promise for novel sensors and faster internet
Mid-infrared light, which has a wavelength longer than visible light but shorter than microwaves, has many important applications in remote sensing and communication technologies. Researchers in Japan have demonstrated the successful operation of several new photonic components that can effectively guide passage of mid-infrared light.