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

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.

Scientists at the U.S. Department of Energy's Argonne National Laboratory have seen a new kind of wave pattern emerge in a thin film of metal oxide, known as titania, when its shape is confined. In the case of titania, this wave pattern caused electrons to interfere with each other in a unique way, which increased the oxide's conductivity, or the degree to which it conducts electricity. This work offers scientists more insight about how atoms, electrons, and other particles behave at the quantum level. Such information could aid in designing new materials that can process information and be useful in electronic applications.

Researchers from Purdue University, the National Research Council of Canada, and the University of Ottawa have used titanium nitride to achieve high-harmonic generation (HHG) in refractory metals for the first time. This achievement could pave the way to focusing the radiation down to the nanoscale for use in nanomachining, nanofabrication, and medical applications, as well as HHG enhancement for the generation of frequency combs for the next generation of nuclear clocks.

Researchers at the University of California San Diego have joined two types of quantum substances: superconducting materials based on copper oxide and nickel oxide-based insulator transition materials. The researchers used these materials to create basic "loop devices" that could be precisely controlled at the nanoscale to reflect the way the brain’s neurons and synapses are connected. Simulating the addition of more loops to the artificial brain would allow the creation of an array of networked devices that display emergent properties, as in an animal's brain.

Researchers at the University of Central Florida have created a new nanomaterial based on fullerenes that is water repellant and can stay dry even when submerged underwater. Fullerenes are bundles of 60 or 70 carbon atoms that form cage-like closed structures. These cages can stack on top of each other to form tall crystals called fullerites. By placing a drop of a gel created from fullerites on any surface, a super water-repellent state is triggered. The discovery could open the door to the development of more efficient water-repellent surfaces, fuel cells, and electronic sensors that can detect toxins. 

MIT researchers have demonstrated that when two single sheets of boron nitride are stacked parallel to each other, the material becomes ferroelectric, a state in which positive and negative charges in the material spontaneously head to different poles. They also discovered that twisting these parallel sheets at a slight angle to each other resulted in a new type of ferroelectric state. Among the potential applications of the new ultrathin ferroelectric material is its use for denser memory storage. Boron nitride is known as “white graphene” because of the similarity of its structure to graphene.