(Funded by the U.S. Department of Defense and the U.S. National Science Foundation)
Researchers from Lehigh University, the U.S. Army Research Laboratory, Arizona State University, and Louisiana State University have developed a nanostructured copper alloy with exceptional thermal stability and mechanical strength, making it one of the most resilient copper-based materials ever created. The breakthrough comes from the formation of copper-lithium precipitates, stabilized by a tantalum-rich atomic bilayer complexion. Unlike typical grain boundaries that migrate over time at high temperatures, this complexion acts as a structural stabilizer, maintaining the nanocrystalline structure, preventing grain growth and dramatically improving high-temperature performance. The U.S. Army Research Laboratory was awarded a U.S. patent for the alloy.

(Funded by the U.S. Department of Defense)
Researchers from The University of Texas at Dallas; Texas State University in San Marcos, TX; and Lintec of America in Plano, TX, as well as international collaborators, have invented a new, inexpensive method in which fibers are coiled to make springlike artificial muscles. What’s unique about this method is that it doesn’t make use of a mandrel – a spindle that serves to support or shape the artificial muscles. The mandrel-free fabrication process involves inserting twist into individual fibers, causing them to coil back on themselves, and then plying the twisted fibers to create springlike coils. The researchers used the mandrel-free method to make high-spring-index carbon nanotube yarns, which could be used to harvest mechanical energy or as self-powered strain sensors.

(Funded by the U.S. Department of Defense and the U.S. National Science Foundation)
Researchers from the City University of New York, Yale University, Caltech, Kansas State University, and international collaborators have discovered a new way of generating phonon-polaritons, a unique type of electromagnetic wave that occurs when light interacts with vibrations in a material’s crystal lattice structure. This advance could pave the way for cheaper, smaller long-wave infrared light sources and more efficient device cooling. The researchers made that discovery by using a thin layer of graphene sandwiched between two hexagonal boron nitride slabs. Until now, exciting and detecting phonon-polariton waves has been expensive – typically involving costly mid-infrared or terahertz lasers and near-field scanning probes – but in this study, the researchers used a cheaper alternative: an electrical current generated by applying an electric field to the graphene.

(Funded by the U.S. Department of Defense, the U.S. Department of Energy and the U.S. National Science Foundation)
Researchers at Caltech have developed an on-chip transducer that converts microwave photons to optical photons. The device involves a tiny silicon beam that vibrates at 5 gigahertz and couples to a microwave resonator – essentially a nanoscale box in which photons bounce around, also at 5 GHz. Using a technique called electrostatic actuation, a microwave photon is converted within that box to a mechanical vibration of the beam, and that mechanical oscillation, with the help of laser light, gets converted by the resonator into an optical photon. Such a conversion could enable the construction of large-scale distributed superconducting quantum computers.

(Funded by the U.S. Department of Defense)
By taking two flakes of special materials that are just one atom thick and twisting them at high angles, researchers at the University of Rochester have unlocked unique optical properties that could be used in quantum computers and other quantum technologies. Until now, scientists have explored the optical and electrical properties of 2D materials when layered on top of one another and twisted at very small angles (typically 1.1 degree). In this study, the researchers twisted layers of a 2D material, called molybdenum diselenide, at up to 40 degrees, and found that the resulting structure produced excitons – essentially, artificial atoms – that can act as quantum information bits, or qubits, and can retain information when activated by light. The research was conducted at the University of Rochester’s Integrated Nanosystems Center.