(7b) High Performance Impact-Tolerant and Abrasion-Resistant Materials: Lessons From Nature

Chitons are marine mollusks found worldwide in the intertidal or subtidal zones of cold water as well as in tropical waters. These organisms have evolved an amazing feeding structure called a Radula. The Radula is a ribbon-like structure that consists of abrasion resistant teeth anchored to a flexible stylus that the organism uses to abrade rocky substrates to reach endolithic and epilithic algae. In this work, we investigate the structure and mineralization process in Cryptochiton stelleri, the largest of the chitons. Using various microscopy and spectroscopy techniques as well as synchrotron analyses, we have uncovered critical structure-function relationships in the mineralized teeth as well as insights into the mineralization processes in these unique structures. Investigation of the mechanical properties of the fully mineralized teeth have revealed that the combination of ultrahard minerals and templating organics, architected in a unique microstructure, lead to a damage tolerant composite that is of the hardest known biominerals known in nature.