In the book Bend, Not Break (Portfolio, 2012), author Ping Fu describes the spirit of resilience as "the ability to bounce back from even the most difficult times." Resilience has become a valued goal in fields such as building construction, national security, and public health, and researchers have begun to focus on material resilience as well. Scientists at McGill University in Montreal have developed this ability in the most unlikely of materials: glass.
Inspired by seashells and other tough natural structures, professor François Barthelat and his team have developed a type of glass that resists fracture. They found that nacre (mother of pearl) is riddled with tiny "weak boundaries" that occur between layers of microstructural blocks. Rather than attempt to model the blocks themselves, the scientists instead recreated the weak boundaries by engraving tiny microfissures in borosilicate glass slides with lasers.
The result was a tremendous success, demonstrating a 200-fold increase of toughness over conventional glass slides. The secret concerns crack propagation: by controlling the path of emerging fissures, the tiny jigsaw-shaped engravings prevent cracks from developing as they would in non-engraved glass.
This strategy parallels similar methods in building construction, namely control joints and expansion joints, that diminish crack propagation and material failure in buildings. The McGill research team's finding reinforces the similarity of material phenomena at different scales, and suggests that architects and materials scientists should collaborate more on similar technical challenges.
Top image: Don LaVange/Flickr via Creative Commons license.
Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.