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

Prior research had suggested that a semiconductor known as rhenium disulfide boasts a prized property: the ability to transport electrons, or conduct electricity, more readily in some directions than others. But measuring, investigating, and manipulating the phenomenon had proven difficult. Now, scientists at the University of Nebraska-Lincoln have measured the flow of electrons in rhenium disulfide with unprecedented levels of precision by layering a nanoscopically thin polymer atop rhenium disulfide. By layering the materials and then flipping the polarization of a narrow sliver within the polymer, the scientists managed to control the flow of electrons in rhenium disulfide.

Being able to deliver drugs directly to diseased cells would improve options for treating diseases. Some radioactive isotopes are already approved to target cancers but when they decay and emit large amounts of energy, this makes it hard to keep them in place near diseased cells or other targets. Researchers are now testing a way to enclose isotopes in tiny pieces of biodegradable material that will keep the isotopes at treatment sites. Scientists at the U.S. Department of Energy’s Oak Ridge National Laboratory are testing whether radioactive medical isotopes enclosed in poly(lactic-co glycolic acid) nanoparticles can keep the drugs at particular cells in the body. 

Chemical engineers at the University of Illinois at Urbana-Champaign have developed a new understanding of how water molecules assemble and change shape in some settings. Their method takes advantage of nanoscale microporous crystals, called zeolites, whose pore spaces can only fit single-molecule-wide chains within their confines. These single-file chains of water molecules have different thermochemical properties than regular, or "bulk," water. The new approach is poised to play a role in helping chemical manufacturers move away from harmful solvent catalysts in favor of water.

Researchers at the University of California, Riverside, the University of California San Diego, and Carnegie Mellon University are studying whether they can turn edible plants, such as lettuce, into mRNA vaccine factories. One of the challenges with mRNA vaccines is that they must be kept cold to maintain stability during transport and storage. If this new project is successful, plant-based mRNA vaccines, which can be eaten, could overcome this challenge by being stored at room temperature. The key is to deliver genetic material to the chloroplast of plants via naturally occurring nanoparticles (viruses) that are engineered so they are not infectious toward plants and humans.

Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a new doping method that could electronically authenticate products before they leave the factory. The doping method consists of implanting small clusters of atoms of a different element from those in the device just beneath its surface. The implanted atoms alter the electrical properties of the topmost layer without harming it, creating a unique label – a nanometer-scale version of a QR code – that can be read by an electronic scanner. Counterfeit devices could be easily identified, because they would not respond to the scanner in the same way.

A UCLA-led team of engineers and chemists has taken a major step forward in the development of microbial fuel cells, generating a power of 0.66 milliwatts per square centimeter—more than double the previous best for microbial fuel cells. To achieve this milestone, the researchers added nanoparticles of silver to electrodes that are composed of a type of graphene oxide. Once inside the bacteria, the silver nanoparticles acted as microscopic transmission wires, capturing electrons produced by the bacteria.

Researchers at the University of Illinois Urbana-Champaign have found a way to make ultrathin surface coatings robust enough to survive scratches and dings. The study found that the rapid evaporative qualities of a specialized polymer containing a network of dynamic bonds in its backbone help form a water-resistant, self-healing coating of nanoscale thickness. The new material, developed by merging thin-film and self-healing technologies, could be used in self-cleaning, anti-icing, anti-fogging, anti-bacterial, anti-fouling, or enhanced heat exchange coatings.

Researchers at the University of California San Diego have developed a new treatment that could keep metastatic cancers at bay from the lungs by using engineered nanoparticles made from the cowpea mosaic virus to target a protein in the lungs. The virus is harmless to animals and humans, but it still registers as a foreign invader, thus triggering an immune response that could make the body more effective at fighting cancer. The idea behind this new treatment is to use the plant virus to help the body’s immune system recognize and destroy cancer cells in the lungs.

Scientists at Northwestern University and the U.S. Department of Energy's Argonne National Laboratory have accidentally discovered a material that is only four atoms thick and allows for studying the motion of charged particles in only two dimensions. The material is a combination of silver, potassium, and selenium in a four-layered structure similar to a wedding cake. The team measured how the ions diffused in this solid and found it to be equivalent to that of a heavily salted water electrolyte, one of the fastest known ionic conductors.

Researchers at Arizona State University have found that clusters of chromium oxide atoms can be fine-tuned to alter their electrical conductance, behaving as wire-like conductors of electricity, semiconductors, or insulators, depending on the number of oxygen atoms present. The results open the door to a new breed of electronics that may soon reach the smallest possible scale, permitting the design of tunable, molecular-sized components that could vastly increase processing and storage capacities in new devices. Such innovations are part of an ongoing change in electronics known as spintronics.