Overcoming the brittleness of glass through bio-inspiration and micro-architecture

• Published in: Nature communications 2014-01, Vol.5 (1), p.3166-3166, Article 3166
• Main Authors: Mirkhalaf, M., Dastjerdi, A. Khayer, Barthelat, F.
• Format: Article
• Language: English
• Subjects: 639/301/1023/218; 639/301/54/989; 639/301/930; Brittleness; Composite materials; Crack propagation; Dental enamel; Energy; Engineering; Humanities and Social Sciences; Minerals; multidisciplinary; Science; Science (multidisciplinary); Teeth
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms4166

Highly mineralized natural materials such as teeth or mollusk shells boast unusual combinations of stiffness, strength and toughness currently unmatched by engineering materials. While high mineral contents provide stiffness and hardness, these materials also contain weaker interfaces with intricate architectures, which can channel propagating cracks into toughening configurations. Here we report the implementation of these features into glass, using a laser engraving technique. Three-dimensional arrays of laser-generated microcracks can deflect and guide larger incoming cracks, following the concept of ‘stamp holes’. Jigsaw-like interfaces, infiltrated with polyurethane, furthermore channel cracks into interlocking configurations and pullout mechanisms, significantly enhancing energy dissipation and toughness. Compared with standard glass, which has no microstructure and is brittle, our bio-inspired glass displays built-in mechanisms that make it more deformable and 200 times tougher. This bio-inspired approach, based on carefully architectured interfaces, provides a new pathway to toughening glasses, ceramics or other hard and brittle materials. Glass is well known to be a brittle material, with fracture occurring soon after crack nucleation. Here, inspired by natural architectures, the authors report the laser patterning of features within an oxide glass, leading to a two order of magnitude improvement in fracture toughness.