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

Researchers from The Pennsylvania State University, the Weizmann Institute of Science in Rehovot, Israel, and the National Institute for Materials Science in Tsukuba, Japan, have developed a measurement technique to probe the proximity-induced superconductivity at the surface of a type of layered material called a heterostructure. Proximity-induced superconductivity is a mechanism to realize a topological superconductor, that is, a superconductor that holds its properties even after undergoing physical changes. The technique used by the researchers involves inserting a layer of graphene, which is a sheet of carbon atoms of one or two atoms thick, between a layer of a topological insulator material (bismuth antimony telluride) and a superconducting material layer (gallium).

Researchers at The University of Texas at Austin have partnered with Smart Material Solutions, Inc. (Raleigh, NC) to develop a new method to keep dust from sticking to surfaces. The result is the ability to make many types of materials dust-resistant, from spacecraft to solar panels to household windows. In experiments, the team changed the geometry of flat surfaces to create a tightly packed nanoscale network of pyramid-shaped structures. These sharp, angular structures make it difficult for dust particles to stick to the material, instead sticking to one another and rolling off the material via gravity.

Engineers at Caltech and the National Institute for Materials Science in Tsukuba, Japan, have discovered that when tungsten diselenide is placed on top of graphene bilayers, graphene's superconductivity is greatly improved. Notably, the superconducting critical temperature – that is, the warmest temperature at which the material can superconduct – is enhanced by a factor of 10. This finding provides new insight into the nature of superconductivity and suggests strategies for enhancing superconductivity in other related graphene-based materials.

Researchers from the University of North Carolina at Chapel Hill and Vanderbilt University have engineered silicon nanowires that can convert sunlight into electricity by splitting water into oxygen and hydrogen gas, a greener alternative to fossil fuels. The silicon nanowires have multiple solar cells along their axis so that they could produce the power needed to split water.

Researchers from The George Washington University, Virginia Tech, the United States Naval Academy, and The University of Texas at Austin have engineered a new nanomaterial that can boost the potency of common disinfectants. The researchers showed that when the nanomaterial is mixed with a peroxide-based disinfectant, the disinfectant is two-to-four times more effective in disabling a coronavirus strain, compared to when the disinfectant is used alone.

Scientists at the University of Massachusetts Amherst have invented a nanowire that can be cheaply grown by common bacteria and tuned to "smell" a vast array of chemical tracers – including those given off by people with different medical conditions, such as asthma and kidney disease. Thousands of these nanowires, each sniffing out a different chemical, can be layered onto tiny, wearable sensors, allowing health-care providers an unprecedented tool for monitoring potential health complications. 

A team of researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, the University of California, Berkeley, and Cornell University has captured real-time movies of copper nanoparticles as they convert carbon dioxide and water into renewable fuels and chemicals – ethylene, ethanol, and propanol, among others. The work was made possible by combining a new imaging technique called operando 4D electrochemical liquid-cell STEM (scanning transmission electron microscopy) with a soft X-ray probe to investigate the same sample environment: copper nanoparticles in liquid.  

Scientists at Rice University have created carbon nanotubes and other hybrid nanomaterials out of plastic waste using an energy-efficient, low-cost, low-emissions process that could also be profitable. "Waste plastic is rarely recycled because it costs a lot of money to do all the washing, sorting, and melting down of the plastics to turn it into a material that can be used by a factory," said Kevin Wyss, the lead author on the study. "We were able to make a hybrid carbon nanomaterial that outperformed both graphene and commercially available carbon nanotubes.”

Physicists from the University of Wisconsin-Madison and the National Institute for Materials Science in Tsukuba, Japan, have directly measured the fluid-like flow of electrons in graphene – an atom-thick sheet of #carbon arranged in a honeycomb pattern – at nanometer resolution for the first time. The researchers used a technique known as scanning tunneling potentiometry (STP) and graphene. They intentionally introduced obstacles in the graphene sheet (spaced at controlled distances) and then applied a current across the sheet. Using STP, they measured the voltage with nanometer resolution at all points on the graphene, producing a two-dimensional map of the electron flow pattern.

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."