(Funded by the U.S. National Science Foundation)
Researchers from Carnegie Mellon University have found a way to control the size and structure of active colloids while yielding more than 100 times the amount created by earlier fabrication methods. The team’s active colloids are linked together using DNA nanostructures – an innovation that makes them flexible, agile, and responsive to signals in their environment. Typically, DNA nanotechnology can only be studied using expensive equipment. In this case, because the DNA is attached to the colloid particles, researchers can observe any nanoscale phenomenon – such as the DNA structures changing shape – in real time by observing changes in the colloid’s movement under a microscope.

(Funded by the U.S. National Science Foundation)
Researchers from Stanford University; the IBM T.J. Watson Research Center in Yorktown Heights, NY; the Korea Electronics Technology Institute in Seongnam-si, South Korea; and Ajou University in Suwon, South Korea, have shown that niobium phosphide can conduct electricity better than copper in films that are only a few atoms thick. Many researchers have been working to find better conductors for nanoscale electronics, but so far the best candidates have had extremely precise crystalline structures, which need to be formed at very high temperatures. The niobium phosphide films made in this study are the first examples of non-crystalline materials that become better conductors as they get thinner, and they can be created at lower temperatures.

(Funded by the U.S. Department of Energy, the U.S. Department of Defense, and the U.S. National Science Foundation)
Scientists from Oregon State University; the Molecular Foundry at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory; Columbia University; and the Autonomous University of Madrid, Spain, have discovered luminescent nanocrystals that can be quickly toggled from light to dark and back again. “Normally, luminescent materials give off light when they are excited by a laser and remain dark when they are not,” said Artiom Skripka, one of the scientists involved in this study. “In contrast, we were surprised to find that our nanocrystals live parallel lives. Under certain conditions, they show a peculiar behavior: They can be either bright or dark under exactly the same laser excitation wavelength and power.”

(Funded by the U.S. Department of Defense, the U.S. Department of Energy, the U.S. National Science Foundation, and the U.S. Department of State)
Researchers from Columbia University; the Molecular Foundry at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory; and the University of Utah have invented new nanoscale sensors of force. They are luminescent nanocrystals that can change intensity and/or color when you push or pull on them. These “all-optical” nanosensors are probed with light only and therefore allow for fully remote read-outs—no wires or connections are needed. The nanosensors have an operational range that spans more than four orders of magnitude in force – a much larger range than any previous optical nanosensor.

(Funded by the U.S. National Science Foundation and the U.S. Department of Defense)
Bright, twisted light can be produced with technology similar to an Edison light bulb, researchers at the University of Michigan have shown. Usually photons from a blackbody source (which is in thermodynamic equilibrium with its environment) are randomly polarized – their waves may oscillate along any axis. The new study revealed that if the emitter was twisted at the micro or nanoscale, with the length of each twist similar to the wavelength of the emitted light, the blackbody radiation would be twisted, too. This discovery adds nuance to fundamental physics while offering a new avenue for robotic vision systems and other applications for light that traces out a helix in space.