(Funded by the National Science Foundation and the U.S. Department of Defense)
Researchers from Penn State, the Massachusetts Institute of Technology (MIT) (including @MIT_ISN), and North Carolina Agricultural and Technical State University have discovered a different version of the Hall effect, called the nonreciprocal Hall effect, which, unlike the conventional Hall effect, does not require a magnetic field. In particular, in this case, the Hall voltage is proportional to the square of the current instead of being proportional to the current. Also, unlike the conventional Hall effect, which is driven by a force induced by the magnetic field, the nonreciprocal Hall effect arises from flowing electrons interacting with platinum nanoparticles. This discovery could lead to applications in the development of quantum communication and harvesting of energy via radio frequencies.

(Funded by the National Institutes of Health and the National Science Foundation)
Researchers from Carnegie Mellon University and the Indian Institute of Technology Bombay in Mumbai, India, have linked the immune response caused by lipid nanoparticles to their lipid chemistry. They found that some lipid structures bind strongly to receptors and others bind weakly. The strong interactions trigger the receptor and ultimately the immune response. The findings will help engineers tailor immune responses when designing lipid nanoparticles for drug delivery. “For vaccines, we might want something that’s more immunogenic, so that the vaccine responds better,” said Namit Chaudhary, one of the scientists involved in this study. “But if we are delivering something to the brain or the liver, for example, we might not want to evoke substantial immune responses that might cause toxicity.”

(Funded by the National Science Foundation and the U.S. Department of Energy)
Researchers from New York University, the U.S. Department of Energy’s Brookhaven National Laboratory, the Korea Advanced Institute of Science and Technology, and the National Institute for Materials Science in Tsukuba, Japan, have pioneered a new technique to identify and characterize atomic-scale defects in a two-dimensional (2D) material called hexagonal boron nitride. The team was able to detect the presence of individual carbon atoms replacing boron atoms in this material. “In this project, we essentially created a stethoscope for 2D materials,” said Davood Shahrjerdi, one of the researchers involved in this study. “By analyzing the tiny and rhythmic fluctuations in electrical current, we can ‘perceive’ the behavior of single atomic defects.”

(Funded by the U.S. Department of Energy and the National Science Foundation)
A nanocrystalline material is made up of many tiny crystals, but as they grow, the nanocrystalline material can weaken. Researchers from Lehigh University, Johns Hopkins University, George Mason University, the University of Tennessee, Knoxville, and the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and Sandia National Laboratories have discovered that the key to maintaining the stability of nanocrystalline materials at high temperatures lies in triple junctions – corners where three of these nanocrystals meet. What the scientists found is that when certain atoms are added to form an alloy, they prefer to occupy sites at these triple junctions, which prevents the nanocrystalline material from losing its strength over time.

(Funded by the National Science Foundation, the U.S. Department of Energy, and the National Institutes of Health)
Using peptides and a snippet of the large molecules in plastics, scientists at Northwestern University have developed materials made of tiny, flexible nano-sized ribbons that can be charged just like a battery to store energy or record digital information. Highly energy efficient, biocompatible and made from sustainable materials, the systems could give rise to new types of ultralight electronic devices while reducing the environmental impact of electronic manufacturing and disposal. “This is a wholly new concept in materials science and soft materials research,” said Samuel I. Stupp, the scientist who led the study. “We imagine a future where you could wear a shirt with air conditioning built into it or rely on soft bioactive implants that feel like tissues and are activated wirelessly to improve heart or brain function.”