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

Researchers from Purdue University and the University of Illinois Urbana-Champaign have created a process to develop ultrahigh-strength aluminum alloys that are suitable for additive manufacturing. The researchers produced the aluminum alloys by using several transition metals, including cobalt, iron, nickel and titanium. "These intermetallics have crystal structures with low symmetry and are known to be brittle at room temperature," said Anyu Shang, one of the researchers involved in this study. "But our method forms the transitional metal elements into colonies of nanoscale, intermetallics lamellae that aggregate into fine rosettes. The nanolaminated rosettes can largely suppress the brittle nature of intermetallics."

As the National Institute for Occupational Safety and Health (NIOSH) Nanotechnology Research Center (NTRC) marks its 20th anniversary, NIOSH celebrates the creative work of the Engineering Controls and Personal Protective Equipment (PPE) critical topic area, one of the ten critical nanotechnology topic areas of the NTRC. NIOSH researchers have conducted laboratory and field research to develop and implement science-based national guidance for respiratory and other PPE to protect against nanomaterial exposures. This blog post highlights major milestones and success indicators of PPE knowledge and advancements.

Researchers from the University of Illinois Urbana-Champaign and Northwestern University have developed and tested a new mathematical model to accurately simulate the effects of blood flow on the adhesion and retention of nanoparticle drug carriers. The model closely corresponded to in vitro experiments, demonstrating the impact that model-based simulations can have on nanocarrier optimization. “There have been studies using mouse models and in vitro tissue models,” said Hyunjoon Kong, one of the researchers involved in this study. “However, we have been designing nanoparticles mostly by trial and error. This is the first kind of demonstration where there is a more systematic, robust design of nanoparticles, under the guidance of physics.”

Researchers from the University of California, Santa Barbara, The Ohio State University, and the University of Hong Kong have, for the first time, characterized the thermoelectric properties of high-quality cadmium arsenide thin films. The researchers created three high-quality films of varying thicknesses – 950 nanometers (nm), 95 nm, and 25 nm – and found that the thinner the material, the higher the thermoelectric sensitivity, resulting in more voltage in response to a temperature gradient, a response enhanced by seven times compared to the state-of-the-art material. These effects were found at near-zero temperatures, so although these thin films can't be deployed for room-temperature applications, they could be useful in cryogenic environments.

Researchers from the U.S. Department of Energy’s Los Alamos National Laboratory (LANL) and Lawrence Berkeley National Laboratory (LBNL) and Seoul National University in South Korea have developed a way to directly measure such materials' thermal expansion coefficient, the rate at which the material expands as it heats. Due to the thinness of two-dimensional materials, until now, measuring their thermal expansion could only be accomplished indirectly or with the use of a support structure called a substrate. The work was conducted at the Molecular Foundry, a user facility at LBNL, and the Center for Integrated Nanotechnologies, a user facility at LANL and the U.S. Department of Energy’s Sandia National Laboratories.

Engineers at the University of California San Diego have developed a pill that releases microscopic robots, or microrobots, into the colon to treat inflammatory bowel disease (IBD). The experimental treatment, given orally, has shown success in mice. It significantly reduced IBD symptoms and promoted the healing of damaged colon tissue without causing toxic side effects. The microrobots are composed of inflammation-fighting nanoparticles chemically attached to green algae cells. The nanoparticles absorb and neutralize pro-inflammatory cytokines in the gut, and the green algae distribute the nanoparticles throughout the colon, accelerating cytokine removal to help heal inflamed tissue.

Researchers from the U.S. Department of Energy's Argonne National Laboratory and Universidad de Zaragoza in Spain have discovered that how calcite is synthesized, or chemically transformed, can dramatically change the internal structure of individual mineral particles. The scientists compared the external shape and internal structure of calcite particles grown by two synthesis approaches. For one synthesis approach, calcite crystals were grown slowly, and a 3D map of the crystal structure inside the calcite particles showed the orderly, repeating patterns scientists expected to see. Using the other synthesis approach, crystals were grown very quickly. This time, a more complex internal structure was seen. Each perfectly shaped calcite crystal was composed of countless nanosized crystalline fragments, or defects. 

Researchers from the University of Michigan, the U.S. Department of Energy’s SLAC National Accelerator Laboratory, Carnegie Mellon University, and Harvard University have discovered that the electrical conductivity of three layers of graphene, in a twisted stack, is similar to that of “magic angle” bilayer graphene. Stacking three layers of graphene introduced an additional twist angle, creating non-repeating patterns, at small-angle twists – unlike bilayer graphene which forms repeating patterns. “This discovery makes fabrication easier, avoiding the challenge of ensuring the precise twist angle that bilayer graphene requires,” said Mohammad Babar, the first author of the study.

University of Missouri researchers have developed a novel 3D printing and laser process to manufacture multi-material, multi-layered sensors, circuit boards, and even textiles with electronic components. The researchers built a machine that has three different nozzles: one nozzle adds ink-like material, another uses a laser to carve shapes and materials, and a third nozzle adds functional materials to enhance the product’s capabilities. The manufacturing process starts by making a basic structure with a regular 3D printing filament. Then, a laser converts some parts into laser-induced graphene. Finally, more materials are added to enhance the functional abilities of the product.

Until now, scientists believed there was a limit to the sharpness of the separation of solutes in water or other fluids that they could achieve with a porous membrane, not only because of variations in pore size but also because of a phenomenon called hindered transport – the internal resistance of the fluid as a solute tries to go through a pore. Now, researchers from the U.S. Department of Energy’s Argonne National Laboratory and the University of Chicago have shown that by using an isoporous membrane, in which all the pores are the same size (approximately 10 nanometers), and by giving the solutes multiple chances to get through the pores, it is possible to surmount hindered transport limitations.