(Funded by the National Science Foundation)
Cornell University researchers have made headway into understanding how twisted bilayer graphene becomes a superconductor. In 2023, the scientists developed a theoretical formalism to compute the highest possible superconducting transition temperature in any material obtained by stacking and twisting two-dimensional materials. For the current work, the scientists applied this theoretical formalism to twisted bilayer graphene. “One of the remarkable properties of twisted bilayer graphene is the associated tunability,” said Debanjan Chowdhury, one of the scientists involved in this study. “You have unprecedented control over temperature and the twist angle – the tiny electric fields that are applied to switch the material from being an insulator versus a superconductor – making it very easy to explore all sorts of exciting regimes in this material.”

(Funded by the U.S. Department of Energy)
Flame aerosol synthesis is used to create nanoparticles that serve as key ingredients in inks and air filters. While effective, this technique has limitations, including challenges with manipulating the flame, achieving precise control over the size and distribution of nanoparticles, and cost. Two new studies, from researchers at the University at Buffalo; the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, Brookhaven National Laboratory, and Lawrence Livermore National Laboratory; and the National Synchrotron Radiation Research Centre in Taiwan have addressed these shortcomings. The studies center on a unique flame aerosol system that is versatile, easy-to-use and cost-effective. In one of the studies, the system was used to create metal-organic frameworks, which are porous nanomaterials; in the other study, the researchers showed that the system could be used to create high-entropy ceramic nanomaterials.

(Funded by the U.S. Department of Defense)
Researchers from the Massachusetts Institute of Technology and the University of Udine in Italy have created a new type of three-dimensional transistor using a unique set of ultrathin semiconductor materials. It features vertical nanowires only a few nanometers wide, which can deliver performance comparable to state-of-the-art silicon transistors while operating efficiently at much lower voltages than conventional devices. The transistor’s extremely small size would enable more of these 3D transistors to be packed onto a computer chip, resulting in fast, powerful electronics that are also more energy-efficient. “This is a technology with the potential to replace silicon, so you could use it with all the functions that silicon currently has, but with much better energy efficiency,” says Yanjie Shao, the scientist who led this study.

(Funded by the National Science Foundation)
Researchers at William & Mary have measured the strength and stretchability of minuscule nanofibrils present in the silk spun by the southern house spider. The core of a spider silk strand is composed of two distinct warps that form helical loops around a central foundation fiber. The tiniest fibers, nanofibrils, are spun into a mesh that surrounds those supporting structures. The researchers found that the nanofibrils in the southern house spider’s silk could stretch 11 times their original length, more than twice the amount of any spider silk previously tested. “As amazing as spider silk as a whole is, looking at these tiny fibrils, they are even stretchier,” said Hannes Schniepp, one of the scientists involved in this study.

(Funded by the National Institutes of Health)
Researchers from Drexel University, the University of Pennsylvania, and Accenture Labs (San Francisco, CA), and Corporal Michael J. Crescenz Veterans Affairs Medical Center (Philadelphia, PA) have built a textile energy grid that can be wirelessly charged. The grid was printed on nonwoven cotton textiles with an ink composed of MXene, a type of nanomaterial that is both conductive and durable enough to withstand the folding, stretching, and washing that clothing endures. The proof-of-concept represents an important development for wearable technology, which, at present, requires complicated wiring and is limited by the use of rigid, bulky batteries that are not fully integrated into garments.