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

Scientists at the U.S. Department of Energy’s Argonne National Laboratory have peeled off heterostructure thin films containing electric bubbles from a particular underlying material, or substrate, while keeping them fully intact. The electric bubbles are nanoscale objects with a radius of about 4 nanometers. The discovery may bring us one step closer to applications – in areas such as microelectronics and energy – that rely upon these unusual brittle structures.

Quantum dots, discovered in the 1990s, have a wide range of applications and are perhaps best known for producing vivid colors in high-end televisions. But for some potential uses, such as tracking biochemical pathways of a drug as it interacts with living cells, progress has been hampered by the tendency of quantum dots to randomly blink off. Now, a team of MIT chemists led by professors affiliated with the Institute for Soldier Nanotechnologies at MIT – a U.S. Army–sponsored MIT interdisciplinary research center – has come up with a way to control this unwanted blinking by firing a beam of mid-infrared laser light for a few trillionths of a second.

The ancient arts of origami, the art of paper-folding, and kirigami, the art of paper-cutting, have gained popularity in recent years among researchers building mechanical metamaterials. Folding and cutting 2D thin-film materials transforms them into complex 3D structures and shapes with unique and programmable mechanical properties. Now, researchers in the United States and China have divided origami- and kirigami-based mechanical metamaterials – artificially engineered materials with unusual mechanical properties – into three categories that include origami-based metamaterials (folding only), kirigami-based metamaterials (cutting only), and hybrid origami-kirigami metamaterials (both folding and cutting).

A research team led by engineers from Rice University has achieved a new benchmark in the design of atomically thin solar cells made of semiconducting perovskites, boosting their efficiency while retaining their ability to stand up to the environment. The researchers discovered that sunlight itself contracts the space between atomic layers in 2D perovskites enough to improve the material's photovoltaic efficiency by up to 18%, an astounding leap in a field where progress is often measured in fractions of a percent.

By using field-emission scanning electron microscopy, researchers from Brigham and Women's Hospital and MIT have discovered a new mechanism by which cancer cells can disarm would-be cellular attackers. The scientists found that cancer cells can evade the immune system by extending nanoscale tentacles into an immune cell to pull out its mitochondria, the cell’s powerpack. These findings give potential new targets for developing the next generation of immunotherapies against cancer.

MIT scientists have demonstrated that nanoparticles containing anti-inflammatory drugs can counteract the early inflammation and damage to knee cartilage caused by injuries and osteoarthritis. The researchers hoped to determine whether osteoarthritis-like disease could be initiated “in a dish” to simulate what happens in humans after a knee injury by using the microgravity environment of the International Space Station. In addition to finding more effective treatments for osteoarthritis, the work in microgravity may lead to understanding how to repair joint damage, which may be crucial for future long-term space missions.

Researchers at Rice University have suggested a method to synthesize borophene, the 2D version of boron. Their calculations show that growing the material on hexagonal boron nitride, an insulator – rather than the more traditional metallic surfaces – could make transfer and manipulation of borophene in experimental studies easier and simpler. 

Researchers at Rice University are developing the world’s first printable military “smart helmet” using an industrial-grade 3D printer that creates a nanomaterial-enhanced exoskeleton with embedded sensors to actively protect the brain against the effects of kinetic energy. The strong-but-light military-grade helmet incorporates advances in materials, image processing, artificial intelligence, haptic feedback, and energy storage.

Any application of ultrashort laser pulses in the visible spectrum needs to overcome a fundamental difficulty – red light travels faster than blue light through transparent materials like glass. So, when an ultrashort laser pulse passes through a glass lens, the tightly packed wavelengths of light separate, destroying the usefulness of the beam. This chromatic dispersion problem has plagued optical researchers for decades. Now, researchers at Harvard University have developed a silicon coating made of nanopillars that, when applied to the surface of a glass lens, can counteract the effects of chromatic dispersion.

Researchers at Northwestern University have developed a new injectable therapy that reverses paralysis and repairs tissue after severe spinal cord injuries. The researchers administered a single injection to tissues surrounding the spinal cords of paralyzed mice. Just four weeks later, the animals regained the ability to walk. A key part of this therapy is that bioactive signals are sent to trigger cells to repair and regenerate. Injected as a liquid, the therapy immediately gels into a complex network of nanofibers that mimic the extracellular matrix of the spinal cord.