Engraving channels in glass slides, inspired by weak areas found in naturally occurring mollusc shells and tooth enamel, dramatically improves toughness of this glass, reports work published in Nature Communications this week. The research finds that further infiltration of these channels with a soft polymer leads to a 200 times increase in toughness compared to non-engraved samples.
Glass is a notoriously brittle material, therefore novel techniques for increasing its toughness, and subsequently its ability to be used in more applications, are being explored. Francois Barthelat and his group systematically studied the distribution of weak boundaries - the internal “edges” that are weaker than the surrounding material - in naturally occurring materials such as tooth enamel and nacre. They observe that a suitable network of these weak boundaries can provide a pathway for, and deflect, propagating cracks, preventing failure and breakage. Using this as inspiration, they laser engrave a 3D network of such weak boundaries into borosilicate glass slides and infiltrate them with polyurethane, resulting in glass that is 200 times tougher than non-engraved samples.
This simple strategy takes its principle from tough materials found in nature, again providing a unique example of a way in which observing the natural world can lead to improved man-made designs.