Mechanics learned from black carp teeth

报告人：Haimin Yao

　　Department of Mechanical Engineering, Hong Kong Polytechnic University

　　Abstract: Many biomaterials in nature possess excellent mechanical properties and therefore are viewed as paradigms for biomimetic materials. Recently, our attention is attracted by black carp, which is a species of fresh-water fish feeding on shelled mollusks such as snails and mussels. In view of the good mechanical properties of the shells of mollusks per se, such unique feeding habit of the black carp may imply the existence of some ingenious strategies for material design in the teeth of black carp. Inspired by this speculation, we conducted comprehensive characterizations and mechanics-based analysis on the black carp teeth. In this talk, I will mainly report two important findings of our study: (i) Under sufficiently high indentation load, black carp teeth tend to fracture through ring cracking. We revealed a fundamental mechanics rule accounting for such inclination to ring cracking, leading to the invention of fracture-mode map; (2) the occlusal surface of the black carp teeth exhibits superior wear resistance compared to the other sections. Such high wear resistance was found to be attributed to the c-axis preferential orientation of the hydroxyapatite crystallites near the occlusal surface. These two findings may not only shed light on the mechanics accounting for the success of black carp teeth in combating the hard mollusk shells but also provide guidelines for the design of biomimetic materials.

　　Speaker: Dr. Haimin Yao is an Assistant Professor working in the Department of Mechanical Engineering at the Hong Kong Polytechnic University. He received his BEng and MEng degrees in Solid Mechanics from Tsinghua University in 2000 and 2002 respectively. After graduation, he went to Germany and studied at the Max-Planck Institute for Metals Research and obtained his Doctor degree in Chemistry from Universität Stuttgart in 2006. Then he moved to USA and worked as a postdoctoral Research Associate at Brown University and Massachusetts Institute of Technology respectively. In 2011, he joined the ME department of the Hong Kong Polytechnic University. The research interests of Dr. Yao include bio-inspired mechanics and materials, and reliability and stability of energy storage materials.

时间： 4月22日上午10:00-11:00

地点：力学一楼 239 会议室

举办： 材料力学行为与设计中科院重点实验室