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

Researchers at the University of California, Berkeley, have developed a battery-independent fluorescent nanosensor based on single-wall carbon nanotubes and an inactive form of an enzyme called glucose oxidase. This nanosensor enables the continuous, reversible, and non-invasive bioimaging of glucose levels in body fluids and tissues. Also, the use of inactive glucose oxidase molecules has major advantages. For example, the manufacturing process of the nanosensors can be simplified, and no toxic byproducts are created. 

Researchers from the University of South Carolina and the University of Colombo in Sri Lanka have developed an artificial intelligence (AI) system that automates the discovery and validation of chemically stable two-dimensional (2D) materials. With this breakthrough technique, the researchers have already found six promising new 2D candidates overlooked by previous manual searches. “The consistent discovery of realistic materials proves these AI techniques can recapitulate human chemical intuition and scientific knowledge to some extent,” said Jianjun Hu, one of the scientists involved in this study. 

Researchers from the California NanoSystems Institute at the University of California, Los Angeles; the Molecular Foundry, a user facility at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory; the University of Maryland; and Xi’an Jiaotong University in China have provided an unprecedented view of the structure and characteristics of medium- and high-entropy alloys. Using an advanced imaging technique, the team mapped, for the first time ever, the three-dimensional atomic coordinates of such alloys. Medium-entropy alloys combine three or four metals in roughly equal amounts; high-entropy alloys combine five or more in the same way. In contrast, conventional alloys are mostly one metal with others intermixed in lower proportions.

Scientists from the U.S. Department of Energy's Pacific Northwest National Laboratory and North Carolina State University have discovered that graphene, a single layer of carbon atoms, can enhance an important property of metals, called the temperature coefficient of resistance. This property explains why metal wires become hot when an electric current runs through them. The researchers were able to reduce the coefficient of resistance of copper by 11% by adding 18 parts per million of graphene without decreasing electrical conductivity at room temperature. This discovery is relevant for the manufacturing of electric vehicle motors.

A joint research effort from the University of Illinois Urbana-Champaign, the U.S. Department of Energy’s National Energy Technology Laboratory and Oak Ridge National Laboratory, and the Taiwan Semiconductor Manufacturing Company has shown how coal can play a vital role in next-generation electronic devices. A process developed by the National Energy Technology Laboratory first converts coal char into nanoscale carbon disks called “carbon dots,” which the University of Illinois research group demonstrated can be connected to form atomically thin membranes for applications in both two-dimensional transistors and memristors – technologies that will be critical to constructing more advanced electronics.

Scientists from the Masonic Medical Research Institute in Utica, NY; the Medical University of South Carolina in Charleston, SC; Stanford University School of Medicine; and McMaster University in Hamilton, Canada, have designed nanomaterials that mimic dead and dying red blood cells. These nanomaterials target and are retained in the spleen to deliver a payload of inhibitors, such as histone deacetylase (HDAC). HDAC and similar chemical inhibitors can be used to treat cancers and other diseases. The researchers demonstrated that HDAC also modulates the inflammatory response, potentially improving the healing response following a heart attack.

Taking inspiration from the human brain, researchers from Northwestern University, Boston College, and the Massachusetts Institute of Technology have developed a new synaptic transistor that can simultaneously process and store information just like the human brain. To create this transistor, the researchers stacked two different types of atomically thin materials: bilayer graphene and hexagonal boron nitride. By rotating one layer relative to the other, the researchers were able to achieve different electronic properties in each graphene layer and, with the right choice of twist, brain-like functionality at room temperature.

Researchers at the National Institute of Standards and Technology and the National Institutes of Health have unveiled a novel fabrication method for shape-shifting probes called geometrically encoded magnetic sensors (GEMS). The scientists developed a precision master mold to construct the probes faster and more cheaply outside of a nanofabrication facility, eliminating the need for specialized instruments. Microscopic magnetic probes containing iron oxide nanoparticles that change shape in response to their environment may enhance magnetic resonance imaging (MRI) technology.

As we look back at the many nanotechnology advances that occurred in 2023, we highlight the top 9 nanotechnology-related stories that generated the most impressions on the NNI LinkedIn page. The Top 3 stories are about a novel device that could dramatically boost the conversion of heat into electricity (#1), a new property of ferroelectric two-dimensional materials (#2), and a laser-based method that could lead to new puncture-resistant materials (#3). 

Engineers at the University of Wisconsin-Madison have developed a vertically aligned carbon nanotube foam that can dissipate a large amount of rotational kinetic energy from an impact. As a helmet lining material, it could mitigate, or even prevent, traumatic brain injuries by weakening rotational kinetic energy before it reaches the brain. "This material shows great promise for enabling new helmets that are drastically better at preventing concussions," says Ramathasan Thevamaran, the engineer who led the research.