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

Engineers at the University of Pennsylvania have solved a major problem preventing metallic wood from being manufactured at meaningful sizes: eliminating the inverted cracks that form as the material is grown from millions of nanoscale particles to metal films big enough to build with. Preventing these defects allows strips of metallic wood to be assembled in areas 20,000 times greater than they were before. Metallic wood is a material that is very strong and light; it is full of regularly spaced nanoscale pores that significantly decrease its density without sacrificing its strength.

Researchers from Washington University in St. Louis and the University of Illinois at Chicago have developed a two-dimensional alloy material made from five metals as opposed to the traditional two. In a first for such a material, the researchers showed that it acted as an excellent catalyst for reducing carbon dioxide into carbon monoxide, with potential applications in environmental remediation.

A research team led by scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the University of California, Berkeley, has developed a nanoparticle composite that grows into 3D crystals. The scientists say that the new material – which they call a 3D polymer-grafted nanoparticle crystal – could lead to new technologies that are 3D-grown rather than 3D-printed.

A team of scientists from Harvard University has created flexible, metal-free electrode arrays that snugly conform to the body’s myriad shapes, from the deep creases of the brain to the fibrous nerves of the heart. The electrode arrays, which can be stretched up to 10 times their length without breaking or tearing, consist of graphene flakes and carbon nanotubes embedded into alginate hydrogels. When living brain cells were grown on these electrode arrays, the cells displayed no damage, suggesting that the electrode arrays could be safely used on living tissues.

A research team at Harvard University has developed an approach in which specifically designed anti-inflammatory nanoparticles could be applied locally and selectively to chronically inflamed muscles that are severely affected or at more immediate risk of deterioration. In a mouse model of Duchenne muscular dystrophy – a genetic disorder characterized by progressive muscle degeneration and weakness – this strategy increased the volume of muscles covered by myofibers and improved muscle functions.

An international team led by researchers at Rice University and the University of Saskatchewan in Canada has developed a technique that may transform chemical catalysis by greatly increasing the number of transition-metal single atoms that can be placed into a carbon carrier. The technique uses graphene quantum dots, which are 3- to 5-nanometer particles of graphene, as anchoring supports. The quantum dots facilitate high-density transition-metal single atoms with enough space between the atoms to avoid clumping.

Engineers at the Institute for Soldier Nanotechnologies (a U.S. Army University-Affiliated Center at MIT), Caltech, and ETH Zürich have shown that nanoarchitected materials – which are designed from precisely patterned nanoscale structures – may be a promising route to lightweight armor, protective coatings, blast shields, and other impact-resistant materials. The researchers fabricated an ultralight material made from nanometer-scale carbon struts that give the material toughness and mechanical robustness. The team tested the material's resilience by shooting it with microparticles at supersonic speeds, and found that the material, which is thinner than the width of a human hair, prevented the miniature projectiles from tearing through it.

Engineers at Duke University have devised a system for manipulating particles approaching 2.5 nanometers in diameter by using sound-induced electric fields. The so-called "acoustoelectronic nanotweezers" provide a label-free, dynamically controllable method of moving and trapping nanoparticles over a large area. Precisely controlling nanoparticles is a crucial ability for many emerging technologies. For example, separating exosomes and other tiny biological molecules from blood could lead to new types of diagnostic tests for the early detection of tumors and neurodegenerative diseases.

By introducing nanoparticles into ordinary cement, researchers at Northwestern University have formed a smarter, more durable, and highly functional cement. The researchers used graphene nanoplatelets, a material rapidly gaining popularity in forming smart materials, to improve the resistance to fracture of ordinary cement. They showed that incorporating a small amount of the nanomaterial improved water transport properties, including pore structure and water penetration resistance, with reported relative decreases of 76% and 78%, respectively.

Engineers at Rice University have created microscopic seeds for growing remarkably uniform 2D perovskite crystals that are both stable and highly efficient at harvesting electricity from sunlight. In laboratory tests, photovoltaic devices made from the 2D perovskite crystals proved both efficient and reliable, a previously problematic combination for devices made from either 3D or 2D perovskites.