Optimal characteristic nanosizes of mineral bridges in mollusk nacre

Abstract

To date, it is still unclear why all mineral bridges linking neighboring platelets in various types of mollusk nacre have sizes of 10–50 nanometers. We answer this question by investigating the strength of platelet–platelet interfaces and found that only when the mineral bridges have diameters of a few tens of nanometers can the interfaces achieve an optimal strength. It is the uniformity of stress distributions in the mineral bridges that dictates their characteristic sizes. The mechanism underlying interfacial optimization via mineral nanobridges simultaneously optimizes the load-bearing efficiency of the materials. This study provides inspirations for the biomimetic design of advanced composite materials.