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

Nearly a decade ago, in collaboration with the Indian government, the National Institute of Biomedical Imaging and Bioengineering (which is part of the National Institutes of Health) spearheaded an international effort to develop a wearable cuffless system. Building on years of research, scientists from The University of Texas at Austin and Texas A&M University are now fine-tuning such a device. Made of graphene, one of the thinnest materials in the world, the device is worn on the underside of the wrist and can measure blood pressure with comparable accuracy to a standard blood pressure cuff. 

Two-dimensional materials can be packed together more densely than conventional materials, so they could be used to make transistors, but one issue holding back these next-generation electronics is the heat they generate when in use and the fact that scientists don't have a good understanding of how 2D materials expand when temperatures rise. Now, researchers from the Massachusetts Institute of Technology and Southern University of Science and Technology in China have demonstrated that they can use laser light to track vibrations of the atoms that comprise 2D materials, allowing the researchers to accurately extract the materials’ thermal expansion coefficients.

Researchers from Rice University, the University of Calgary, the University of Washington, and the South Dakota School of Mines and Technology have used Rice University's unique flash Joule heating process to convert asphaltenes, a byproduct of crude oil production, instantly into turbostratic (loosely aligned) graphene and mix it into composites for thermal, anti-corrosion and 3D-printing applications. The process makes good use of material otherwise burned for reuse as fuel or discarded into tailing ponds and landfills. 

Researchers at the U.S. Department of Energy’s Brookhaven National Laboratory have developed a new way to guide the self-assembly of a wide range of novel nanoscale structures using simple polymers as starting materials. Under an electron microscope, these nanometer-scale structures look like tiny Lego building blocks, including parapets for miniature medieval castles and Roman aqueducts. The work could help guide the design of custom surface coatings with tailored optical, electronic, and mechanical properties, for use in sensors, batteries, and filters.

Researchers at Stanford University have developed a new material for printing at the nanoscale and used it to print minuscule lattices that are both strong and light. The researchers demonstrated that the new material can absorb twice as much energy than other 3D-printed materials of comparable density. In the future, their invention could be used to create better lightweight protection for fragile pieces of satellites, drones, and microelectronics.

Researchers at the National Institute of Standards and Technology have created grids of tiny clumps of atoms known as quantum dots and studied what happens when electrons dive into these nanoparticles. The researchers made multiple 3-by-3 grids of precisely spaced quantum dots, each comprising one to three phosphorus atoms. Attached to the grids were electrical leads and other components that enabled electrons to flow through them. The grids provided playing fields in which electrons could behave in nearly ideal, textbook-like conditions, free of the confounding effects of real-world materials.

Researchers from Oregon State University and Oregon Health & Science University have developed a method for producing nanoparticles that can reach temperatures in cancer lesions of up to 50 degrees Celsius (122 degrees Fahrenheit) when exposed to an alternating magnetic field. Magnetic nanoparticles have shown anti-cancer potential for years, but they can only be used in patients whose tumors are accessible by a hypodermic needle (that is, not for people with hard-to-reach malignancies, such as metastatic ovarian cancer). In the case of this study, the nanoparticles can accumulate in metastatic ovarian cancer tumors and, when exposed to an alternating magnetic field, can rise in temperature to 50 degrees Celsius.

Researchers from the University of Chicago, the University of Southern California, the U.S. Department of Energy’s Argonne National Laboratory, and Tongji University in China have developed a skin-like device that consists of a thin film of a plastic semiconductor combined with stretchable gold nanowire electrodes. Even when stretched to twice its normal size, their device functioned as planned without formation of any cracks.

Researchers from the Massachusetts Institute of Technology, the University of Minnesota, and the Samsung Advanced Institute of Technology in South Korea have developed a new kind of camera that can detect terahertz pulses rapidly, with high sensitivity, and at room temperature and pressure. The new system uses nanoparticles, called quantum dots, which can emit visible light when stimulated by terahertz waves. The visible light can then be recorded by a device that is similar to a standard electronic camera's detector and can even be seen with the naked eye. 

Researchers at Rice University have described a strategy by which constraining carbon feedstock in a furnace helps to control the growth of nanotubes. In this method, a nanotube begins to form at the metal catalyst on a substrate, but lifts the catalyst as it grows, looking like a kite on a string.