Font Size: 

Nacre is the iridescent layer found inside many mollusk shells. This natural composite is mostly made of microscopic ceramic tablets bonded by a small fraction of organic materials. Nacre is 3,000 tougher that the ceramic it is made of, and its remarkable structure is now inspiring the design of novel biomimetic composites. The aim of this work is to characterize the microstructures and micromechanisms behind this remarkable performance. Deformation and fracture experiments were performed on millimeter size specimens from four types of nacres, using a miniature loading stage and in-situ microscopy. Nacre from pearl oyster showed to be the toughest of the nacres tested, with distinct and quite unusual deformation and fracture patterns. Microstructure-based finite element models are being developed in order to capture and quantify key microscale toughening mechanisms.