A cracked smartphone screen's no good. But future phones may be sold with cracks built in—because a network of tiny cracks can actually toughen up a piece of glass.

The crack research team borrowed the concept from mother-of-pearl, the iridescent stuff in abalone shells. It's 3000 times stronger than the mineral it's made of, due to its jigsawlike construction.

Using a 3-D laser engraver—the tool used to make those glass trophies with a logo floating inside—the researchers carved cracks a few microns wide into glass slides, and filled the cracks with polyurethane. The resulting glass was 200 times tougher, because the microcracks dissipate energy, preventing larger cracks. The study is in the journal Nature Communications. [M. Mirkhalaf, A. Khayer Dastjerdi and F. Barthelat, Overcoming the brittleness of glass through bio-inspiration and micro-architecture]

The cracks in this study are visible—so, not suitable for a smartphone screen. But the researchers say it's possible to shrink them down to less than a micron wide, an imperceptible size. As to whether crack-proof screens are a good business model, well, how much are you willing to shell out for an unbreakable phone?

—Christopher Intagliata

[The above text is a transcript of this podcast.]

[Scientific American is part of Nature Publishing Group.]