How to Sculpt a Crystal

Many important materials such as steel are made up of a large number of small crystals—called crystallites or grains—and their sizes and shapes can affect the material’s properties. Now researchers have shown how to “sculpt” crystallites into any arbitrary shape, at least in a two-dimensional crystal made of tiny beads. The researchers found that the grain interfaces are malleable and tend to move toward a region that has been disturbed by a laser beam. The technique could lead to new ways of studying crystallites and to a new method for developing “designer” materials starting from microscopic structures.