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

Researchers at Columbia University, the Technical University of Denmark, Aarhus University in Denmark, Université Paris-Saclay, and the National Institute for Materials Science in Tsukuba, Japan, have developed a simple new fabrication technique that may help physicists probe the fundamental properties of twisted layers of graphene and other 2D materials in a more systematic and reproducible way. They used long "ribbons" of graphene, rather than square flakes, to create devices that offer a new level of predictability and control over both twist angle and strain. The researchers showed that with just a little push from the tip of an atomic force microscope, they can bend a graphene ribbon into a stable arc that can then be placed flat on top of a second, uncurved, graphene layer.

Researchers at the University of Chicago have found that a sheet of glass crystal just a few atoms thick could trap and carry light. This discovery demonstrates what are essentially 2D photonic circuits. Photonic circuits already exist, but they are larger and three-dimensional, and particles of light, or photons, travel enclosed inside the waveguides used in these circuits. (Waveguides act like the wires that are used to carry electrical signals, but they carry photons instead.) With this system, the glass crystal is thinner than a photon – so, part of a photon actually sticks out of the crystal, as it travels. This work made use of the fabrication facilities of the Pritzker Nanofabrication Facility at the University of Chicago, which receives support from SHyNE Resource, a node of the National Nanotechnology Coordinated Infrastructure.

In rooms where smoking has taken place regularly, tobacco's imprint lingers on indoor surfaces, even long after regular smoking has stopped. The leftover residues, known as thirdhand smoke, can be a long-term source of indoor pollutants. Now, researchers from the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), the University of California Berkeley, the University of California Riverside, and San Diego State University, have examined smoke-contaminated aged carpets and new carpets exposed to fresh smoke in the lab and found that carpets can be an important reservoir and source of contaminants from thirdhand smoke. The work was carried out at Berkeley Lab’s Air Quality Testing Laboratory and the Molecular Foundry, a user facility at Berkeley Lab. 

Researchers from the University of Missouri have developed a new method using nanopores – nanometer-sized holes – to help scientists advance their discoveries in neuroscience. "Potential applications include studying the structures of DNA- and RNA-based diseases and disorders,” said Li-Qun "Andrew" Gu, one of the scientists involved in this study. “Or we could potentially discover new small-molecule drug compounds that can be used in future drug discoveries."

Scientists from Rice University, Cornell University, the Army Research Laboratory, the Naval Research Laboratory, and the Indian Institute of Technology Kanpur mixed hexagonal boron nitride – a soft variety also known as "white graphite" – with cubic boron nitride – a material second to diamond in hardness – and found that the resulting nanocomposite interacted with light and heat in unexpected ways that could be useful in next-generation microchips and quantum devices. "What is fascinating about this study is that it opens up possibilities to tailor boron nitride materials with the right amounts of hexagonal and cubic structures, thus enabling a broad range of tailored mechanical, thermal, electrical, and optical properties in this material," said Pulickel Ajayan, one of the scientists involved in this study.

Engineers at Johns Hopkins University have developed nanoscale tattoos – dots and wires that stick to live cells, while flexing and conforming to the cells' wet and fluid outer structure. "If you imagine where this is all going in the future, we would like to have sensors to remotely monitor and control the state of individual cells and the environment surrounding those cells in real time," said David Gracias, the engineer who led the development of this technology. "If we had technologies to track the health of isolated cells, we could maybe diagnose and treat diseases much earlier and not wait until the entire organ is damaged."

By fusing DNA and glass, researchers have made an impressive material that, they say, is both stronger and lighter than steel. The researchers made use of a technique in which DNA self-assembles to form a chemical skeleton. Then, this DNA architecture is encased in a layer of a glass-like material only hundreds of atoms thick. "The ability to create designed 3D framework nanomaterials using DNA and mineralize them opens enormous opportunities for engineering mechanical properties," said Oleg Gang, a nanomaterials scientist at Columbia University who was involved in this study. The research used resources at the Center for Functional Nanomaterials, a user facility at the U.S. Department of Energy’s Brookhaven National Laboratory.

Researchers from Penn State, Western Michigan University, and the U.S. Department of Energy’s Oak Ridge National Laboratory have found that atomic-scale steps on sapphire substrates enable crystal alignment of 2D materials during semiconductor fabrication. They also discovered that manipulation of these materials during synthesis may reduce defects and improve electronic device performance.

Researchers at the Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania have developed a proof-of-concept model for delivering gene-editing tools to treat blood disorders. Their approach uses mRNA encapsulated in lipid nanoparticles as a technology platform to carry out in vivo cellular reprogramming, modifying diseased blood cells directly within the body. Use of this platform in clinical settings could expand access and reduce the cost of gene therapies for blood disorders, many of which currently require chemotherapy and a stem cell transplant.

Researchers at Vanderbilt University have shown that a type of engineered nanostructured surface can be used to trap micrometer and sub-micrometer particles within seconds. The researchers state that the enhanced absorption of light in the nanostructures helps in the transport of analytes to biosensing surfaces and could help in the detection of cancer.