Category Physics

This computer-generated model shows the spherical core of the quantum dot nanoparticle (in red) along with the ‘flying saucer’ shape of the outer shell (in yellow). The tension in the core induced by the shell affects the electronic states and lowers the energy threshold required to trigger the laser. Credit: Alex Voznyy

This tiny US flag — just a few nanometers wide and invisible to the naked eye — is arguably the world’s smallest image of Old Glory, according to its creators at the University of Texas at Dallas. In an experiment, the nanoflag pattern emerged unexpectedly as sheets of the “stripe” material — molybdenum ditelluride — were heated to about 450 degrees Celsius, at which point its atoms began to rearrange and form new structures — the ‘stars’ in this false-color image. Each star consists of six central atoms of molybdenum surrounded by six atoms of tellurium. Stacked on top of one another, the stars form nanowires that might power advanced electronics. The transformation from stripes to stars is reported in the journal Advanced Materials. Credit: University of Texas at Dalla

These are examples of the silk used in experiments to detect damage in composites, shown under black light. (Left) Ordinary fibroin of the Bombyx mori silk worm. The observed fluorescence is the result of molecules already present in the protein structure of the fiber. (Middle) Mechanophore-labeled silk fiber fluoresces in response to damage or stress. (Right) Control sample without the mechanophore. Credit: Chelsea Davis and Jeremiah Woodcock/NIST

Researchers may have a new solution to your slow wifi.
Credit: © wladimir1804 / Fotolia