New Type of Glass Inspired by Nature is More Resistant to Impacts

Using the iridescent mother-of-pearl often found lining seashells, researchers have engineered a new composite glass with a greatly boosted resistance to impacts. Strategies to make glass more impact-resistant include lamination, which bonds two or more glass plates together with thin layers of resin or other polymers in between, and tempering, which toughens glass through reheating and rapid cooling. However, Barthelat and his colleagues think they can do better by looking to nature for inspiration. For the past 15 years, they have focused on the structure and mechanics of mother-of-pearl, an opalescent impact-resistant material, also known as nacre, that helps shield the soft bodies of mollusks from strong predator jaws. “Animals take relatively weak ingredients — a brittle mineral, soft proteins — and turn them into a hard yet extremely tough armor,” Barthelat said. The key to nacre’s toughness lies in how the material is built like a brick wall, composed of stacked layers of flat microscopic mineral tablets mortared together by proteins. These brittle calcium carbonate bricks can slide past one another when under stress, helping nacre absorb impacts. To mimic nacre, the researchers used a pulsed ultraviolet laser beam to etch square or hexagonal patterns onto regular borosilicate glass sheets 220 microns thick, or roughly twice the average width of a human hair. These engraved plates were then laminated with thin layers of plastic each 125 microns thick. During this process, the glass sheets are separated into individual tiles, each about 1 to 4 millimeters wide.

Learn more (opens external site)