Glass is strong—until it shatters. If it could stretch more like a rubber band, glass could be used in shatter-proof windows and flexible electronic displays or fashioned into mechanical sensors that could operate at the high temperatures encountered in such fields as aeronautics. Materials scientists led by Seiji Inaba of the Tokyo Institute of Technology have created the first such elastic glass.
Glass is typically made up of phosphorus- or silicon-based molecules tightly bound to one another in orderly but noncrystalline three-dimensional structures. Inaba and his colleagues designed their glass so its molecular structure would instead resemble chains of rubbery materials; its relatively long chains of phosphorus oxide are weakly connected to one another. After the scientists stretched this glass at high temperatures, its fibers shrank by about 35 percent—demonstrating elasticity, a behavior not seen in glasses before. The stretchy glass was described online last December in Nature Materials. (Scientific American is part of Nature Publishing Group.)
Inaba, who now works at Asahi Glass in Yokohama, says he still has work to do. So far the glass contracts well at 220 to 250 degrees Celsius, but ultimately designers want such performance closer to room temperature. Michael Demkowicz, a materials scientist at the Massachusetts Institute of Technology, notes that engineers could use Inaba's recipe to modify a glass that is, say, already known as a good conductor and make it elastic, too. Maybe someday soon a dropped phone or wineglass will be a far less shattering experience.