title: A laser-engraved glass duplicating the structure, mechanics and performance of natural nacre.
abstract: Highly mineralized biological materials such as nacre (mother of pearl), tooth enamel or conch shell boast unique and attractive combinations of stiffness, strength and toughness. The structures of these biological materials and their associated mechanisms are now inspiring new types of advanced structural materials. However, despite significant efforts, no bottom up fabrication method could so far match biological materials in terms of microstructural organization and mechanical performance. Here we present a new 'top down' strategy to tackling this fabrication problem, which consists in carving weak interfaces within a brittle material using a laser engraving technique. We demonstrate the method by fabricating and testing borosilicate glasses containing nacre-like microstructures infiltrated with polyurethane. When deformed, these materials properly duplicate the mechanisms of natural nacre: combination of controlled sliding of the tablets, accompanied with geometric hardening, strain hardening and strain rate hardening. The nacre-like glass is composed of 93 volume % (vol%) glass, yet 700 times tougher and breaks at strains as high as 20%.
authors.affiliation: Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada.
authors.forename: Seyed Mohammad Mirkhalaf
authors.initials: SM
authors.lastname: Valashani
authors.forename: Francois
authors.initials: F
authors.lastname: Barthelat
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis*; D055119:Elastic Modulus / Q000528:radiation effects; D005898:Glass / Q000737:chemistry* / Q000528:radiation effects*; D006244:Hardness / Q000528:radiation effects; D007834:Lasers; D008422:Materials Testing; D060734:Nacre / Q000737:chemistry*; D013499:Surface Properties / Q000528:radiation effects; D013718:Tensile Strength / Q000528:radiation effects; D014783:Viscosity / Q000528:radiation effects
chemical_list: D060734:Nacre