Since 2004, materials scientists and nanotechnologists have been excited about a special of arrangement of atoms called a "coherent twin boundary" that can add strength and other advantages to metals like gold and copper. The CTB's are often described as "perfect," appearing like a one-atom-thick perfectly-flat plane in models and images. New research at the University of Vermont and Lawrence Livermore National Laboratory shows that these boundaries are not so perfect after all. Even more surprising, the newly discovered kinks and defects appear to be the cause of the CTB's strength.This image shows a simulation of atoms in a coherent twin boundary (shown in red) in copper. The newly discovered "kink" defects appear as green step-like structures and folds in the red areas. The red twin boundaries extend between columns of green atoms which represent grain boundaries within the copper.