Microstructure and Mechanical Properties of the Dactylopodites of the Chinese Mitten Crab (Eriocheir sinensis)

• Main Authors: Ying Wang, Xiujuan Li, Jianqiao Li, Feng Qiu
• Format: Article
• Language: English
• Published: MDPI AG 2018-04-01
• Series: Applied Sciences
• Subjects: dactylopodite; microstructure; composition; mechanical properties
• Online Access: http://www.mdpi.com/2076-3417/8/5/674

The dactylopodites of the Chinese mitten crab (Eriocheir sinensis) have evolved extraordinary resistance to wear and impact loading after direct contact with rough surfaces or clashing with hard materials. In this study, the microstructure, components, and mechanical properties of the dactylopodites of the Chinese mitten crab were investigated. Images from a scanning electron microscope show that the dactylopodites’ exoskeleton was multilayered, with an epicuticle, exocuticle, and endocuticle. Cross sections and longitudinal sections of the endocuticle revealed a Bouligand structure, which contributes to the dactylopodites’ mechanical properties. The main organic constituents of the exoskeleton were chitin and protein, and the major inorganic compound was CaCO3, crystallized as calcite. Dry and wet dactylopodites were brittle and ductile, respectively, characteristics that are closely related to their mechanical structure and composition. The findings of this study can be a reference for the bionic design of strong and durable structural materials.