Glass is one of the most useful materials in our modern world, but being prone to cracking or shattering is a major downside. Scientists at McGill University have developed a new type of glass inspired by the mollusk shell that’s stronger and tougher, while retaining good transparency.
That inner, iridescent layer of a mollusk shell is actually the secret to its strength. Known as nacre or mother-of-pearl, the material’s microscopic structure resembles brickwork, with platelets of a stiff calcium carbonate interspersed with soft, elastic biopolymers. This structure not only improves strength but stops cracks from propagating.
In previous work the McGill researchers mimicked nacre by etching microscopic cracks into glass using lasers, and while that worked to improve strength and toughness, it reduced transparency. For the new study, the team replicated the structure using a composite of glass flakes and acrylic, which act like the stiff platelets and soft elastic, respectively.
To make sure the material remains transparent, the researchers tuned the refractive index of the acrylic so that it matched that of the glass. The end result is a material that’s much stronger and tougher than regular glass, but still transparent.
“Until now there were trade-offs between high strength, toughness, and transparency,” says Allen Ehrlicher, corresponding author of the study. “Our new material is not only three times stronger than the normal glass, but also more than five times more fracture resistant.”
The team says that the method should be scalable, and the resulting material could be useful for making stronger displays for smartphones and other devices. In future work the researchers plan to investigate ways to change the color, conductivity and other properties of the material.
Seashell-inspired glass promises shatterproof smartphone screens [New Atlas]