Press Releases: Research Funded by Agencies Participating in the National Nanotechnology Initiative

Researchers from The Ohio State University, the University of Texas at Dallas, and the National Institute for Materials Science in Tsukuba, Japan, have shown that quantum geometry plays a key role in allowing graphene, when twisted to a precise angle – called the magic angle – to become a superconductor, moving electricity with no loss of energy. In a conventional metal, high-speed electrons are responsible for conductivity. But twisted bilayer graphene has a type of electronic structure in which the electrons move very slowly – in fact, at a speed that approaches zero if the angle is exactly at the magic one. "We can't use the speed of electrons to explain how the twisted bilayer graphene is working," said Marc Bockrath, one of the scientists involved in this study. "Instead, we had to use quantum geometry."

Chemists at Northwestern University have designed a new photonic lattice with properties never before seen in nature. In solid materials, atoms must be equally spaced apart and close enough together to interact effectively. The new architectures are based on stacked lattices of nanoparticles that show interactions across unprecedentedly large distances. Because the nanoparticles can communicate across ultralong distances, the stacked architecture offers potential applications in remote sensing and detection. “This is an entirely new class of engineered materials that have no counterpart or analogue in nature," said Teri Odom, a senior author of the study.

Scientists at the University of Pennsylvania have developed a lipid nanoparticle that can target and deliver messenger RNA (mRNA) to cells in the placenta. Once these cells receive the mRNA, they create vascular endothelial growth factor, a protein that helps expand the blood vessels in the placenta to reduce the mother's blood pressure and restore adequate circulation to the fetus. The researchers' successful trials in mice may lead to promising treatments for preeclampsia in humans. "This treatment would be administered intravenously,” said Kelsey Swingle, the lead author on this study. “That means a pregnant woman would be able to be treated via a simple, non-invasive, and pain-free IV drip."

Despite advancements in cooling solutions, the interface between an electronic chip and its cooling system has remained a barrier for thermal transport due to the materials' intrinsic roughness. Now, researchers from Carnegie Mellon University and the Massachusetts Institute of Technology have built a flexible, powerful, and highly reliable material to efficiently fill the gap. The material is composed of two thin copper films with a graphene-coated copper nanowire array sandwiched in between. The sandwich material consists of a thermal interface material that has twice the thermal conductance of current state-of-the-art thermal interface materials.

Researchers from Florida State University and BNNT Materials (Newport News, VA) have completed the first-ever study on how purified boron nitride nanotubes remain stable in extreme temperatures in inert environments. Boron nitride nanotubes are stronger and more resistant to high temperatures than carbon nanotubes, but manufacturing these materials is challenging. The researchers found that boron nitride nanotubes are fully stable at up to 1,800 degrees Celsius in an inert environment, the chemically inactive atmosphere in which they are manufactured. 

Researchers from Pennsylvania State University and McMaster University in Canada have created two-dimensional oxides, materials with special properties that can serve as an atomically thin insulating layer between layers of electrically conducting materials. The oxides showed good properties for use in stacked materials called heterostructures that can enable electrons to travel vertically through the structure instead of horizontally like conventional electronic devices.

Researchers from the Massachusetts Institute of Technology, the Georgia Institute of Technology, the University of Virginia, Washington University in St. Louis, Sejong University (Seoul, South Korea), Yonsei University (Seoul, South Korea) have developed a new process based on two-dimensional (2D) materials to create light-emitting diode (LED) displays with smaller and thinner pixels. The study shows that the world's thinnest and smallest pixeled displays can be enabled by an active layer separation technology using 2D materials, such as graphene and boron, to enable high array density micro-LEDs.

Scientists from the U.S. Department of Energy’s Lawrence Livermore National Laboratory, Sandia National Laboratories, and Lawrence Berkeley National Laboratory, as well as the Indian Institute of Technology in Gandhinagar, India, have created 3–4 nanometer ultrathin nanosheets of a metal hydride that increase hydrogen storage capacity. Hydrogen has the highest energy density of any fuel and is considered a viable solution for ground transportation, aircraft, and marine vessels. The material created in this most recent collaboration came from solvent-free mechanical exfoliation in zirconia, yielding a material that is only 11–12 atomic layers thick and can hydrogenate to about 50 times the capacity of the bulk material.

Researchers from the U.S. Department of Energy’s SLAC National Accelerator Laboratory and Argonne National Laboratory, as well as Stanford University, Cornell University, the University of California, Berkeley, North Carolina State University, the University of Arkansas, and the University of Toulouse in France have discovered a size threshold beyond which antiferroelectric materials lose those properties, becoming ferroelectric. To explore how an antiferroelectric material's properties may change at small scales, the researchers focused on lead-free sodium niobate membranes. “We found that when [these] membranes were thinner than 40 nm, they become completely ferroelectric,” said Ruijuan Xu, one of the scientists involved in this work. “And from 40 nm to 164 nm, we found that the material had some regions that were ferroelectric, while other regions were antiferroelectric."

Researchers at Yale University have discovered surprising wire-like properties of a protein made by electricity-producing bacteria that show similarity to those of methane-eating microbes. This protein nanowire allows bacteria to produce to highest electric power reported possible so far and explains how these bacteria can survive without oxygen-like membrane-ingestible molecules. But to date, no one had discovered how they are made and why they are so conductive. Using high-resolution cryo-electron microscopy, the researchers were able to see the nanowire's atomic structure.