(Funded by the U.S. National Science Foundation)
Researchers at Northwestern University have created a new platform for monitoring chemical contaminants in the environment. The platform can detect the metals lead and cadmium at concentrations down to two and one parts per billion, respectively, in a matter of minutes. It was created by interfacing nanomechanical microcantilevers with synthetic biology biosensors. When the tiny cantilevers are coated with DNA molecules, biosensing molecules bind to the DNA, causing the cantilevers to bend. When exposed to toxic metals, the biosensors unbind, causing the cantilever to “de-bend,” which can be measured precisely to detect the toxic metals.

(Funded by the U.S. Department of Energy, the U.S. Department of Defense, and the U.S. National Science Foundation)
Researchers from the Molecular Foundry, a user facility at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, Columbia University, and Universidad Autónoma de Madrid in Spain have developed a new optical computing material from photon-avalanching nanoparticles. This approach offers a path toward realizing smaller, faster components for next-generation computers by taking advantage of intrinsic optical bistability – a property that allows a material to use light to switch between two different states, such as glowing brightly or not at all. For decades, researchers have sought ways to make a computer that uses light instead of electricity. But in previous studies, optical bistability had almost exclusively been observed in bulk materials that were too big for a microchip and challenging to mass produce. Now, the researchers suggest that the new photon-avalanching nanoparticles could overcome these challenges in realizing optical bistability at the nanoscale.

(Funded by the U.S. Department of Energy)
Scientists from the Massachusetts Institute of Technology and the National Institute for Materials Science in Tsukuba, Japan, have discovered that electrons can form crystalline structures in materials composed of either four or five layers of graphene. (Graphene is a one-atom-thick layer of carbon atoms arranged in hexagons, which looks like a honeycomb structure.) Last year, the scientists reported that electrons became fractions of themselves upon applying a current to a material composed of rhombohedral pentalayer graphene and hexagonal boron nitride. This time, the scientists have shown that electrons can become fractions of themselves without a magnetic field. They also found that what they saw last time can be understood to emerge in an electron “liquid” phase, analogous to water, and what they have now observed can be interpreted as an electron “solid” phase that looks like the formation of electronic “ice.”

(Funded by the U.S. Department of Defense and the U.S. National Science Foundation)
Researchers at the Massachusetts Institute of Technology (MIT), Brown University, and the Rhode Island School of Design in Providence, RI, have developed an autonomous programmable computer in the form of an elastic fiber, which could monitor health conditions and physical activity, alerting the wearer to potential health risks in real time. Clothing containing the fiber computer was comfortable and machine washable, and the fibers were nearly imperceptible to the wearer, the researchers report. “Our bodies broadcast gigabytes of data through the skin every second in the form of heat, sound, biochemicals, electrical potentials, and light, all of which carry information about our activities, emotions, and health. Wouldn’t it be great if we could teach clothes to capture, analyze, store, and communicate this important information in the form of valuable health and activity insights?” says Yoel Fink, senior author of a paper on the research and principal investigator in MIT’s Research Laboratory of Electronics and the Institute for Soldier Nanotechnologies at MIT.

(Funded by the U.S. Department of Energy and the U.S. National Science Foundation)
Researchers from the University of Connecticut; Harvard University; the Massachusetts Institute of Technology; RTX BBN Technologies in Arlington, VA; and the National Institute for Materials Science in Tsukuba, Japan, have discovered that electrons in twisted trilayer graphene behave unlike those described by Bardeen-Cooper-Schrieffer theory of paired electrons. However, twisted trilayer graphene shares properties with high-temperature cuprates, in which electrons also pair up, but differently from traditional superconductors. Many previous studies in graphene are limited in describing superconductivity, because those experiments focus on the properties of single electrons rather than electron pairs, says Pavel Volkov, one of the researchers involved in this study. “What matters is that electrons form pairs, and somehow you want to probe the properties of those pairs to be able to study superconductivity,” he says.