“Mollusk shells are made up of about 95 per cent chalk, which is very brittle in its pure form,”. “But nacre [ parelmoer ], or mother-of-pearl, which coats the inner shells, is made up of microscopic tablets that are a bit like miniature Lego building blocks, is known to be extremely strong and tough, which is why people have been studying its structure for the past twenty years.”
Previous attempts to recreate the structures of nacre have proved to be challenging.
Now these scientist chose to do was to study the internal ‘weak’ boundaries or edges to be found in natural materials like nacre and then use lasers to engrave networks of 3D micro-cracks in glass slides in order to create similar weak boundaries. The results were dramatic.
The researchers were able to increase the toughness of glass slides (the kind of glass rectangles that get put under microscopes) 200 times compared to non-engraved slides. By engraving networks of micro-cracks in configurations of wavy lines in shapes similar to the wavy edges of pieces in a jigsaw puzzle in the surface of borosilicate glass, they were able to stop the cracks from propagating and becoming larger. They then filled these micro-cracks with polyurethane, although according the scientist, this second process is not essential since the patterns of micro-cracks in themselves are sufficient to stop the glass from shattering.
Bron, lees meer:
Mc Gill university
Publicatie:
M. Mirkhalaf, et al.: Overcoming the brittleness of glass through bio-inspiration and micro-architecture
