BIO-INSPIRED , LIGHTWEIGHT , STIFF , AND TOUGH STRUCTURES
PETER MEANS FOR VIRGINIA TECH
Cuttlefish , like octopuses and squid , are cephalopods that have been trolling the oceans for about 500 million years , long before the first shark or fish ever evolved . Completely different from the soft swim bladders of fishes , cuttlefishes use a highly porous but stiff bioceramic cuttlebone for buoyancy regulation . It is fascinating how this porous internal skeleton , with more than 90 % porosity , can withstand strong water pressure as high as 60 atm for some cuttlefish species .
Assistant Professor Ling Li and his team have employed synchrotron-based micro-computed tomography , in-situ mechanical tests , digital image correlation , and finite element analysis to elucidate the mechanics of cuttlebone . Their findings , recently published in PNAS , report that the chambered microstructure of the cuttlebone , which consists of vertical walls and horizontal septa , allows for lightweight , high stiffness , and damage tolerance simultaneously — the result of an optimal waviness gradient evolved by the vertical walls over time . Additionally , the wavy and corrugated walls regulate the damage to well-defined locations and enhance the energy absorption capability of cuttlebone impressively to values comparable to engineering metal foams .
The design principles found in cuttlebone can inspire the design of novel lightweight cellular ceramics , which may have a range of potential applications in packing , transportation , and infrastructure . The authors include ME graduate students Ting Yang , Hongshun Chen , Zhifei Deng , and Liuni Chen , undergraduate student Wenkun Liu , and post-doc Zian Jia . This work is supported by Air Force Office of Scientific Research through the Young Investigator Award .
Ling Li Assistant Professor
Ling Li inspects a cuttlefish bone .
VIRGINIA TECH MECHANICAL ENGINEERING ANNUAL REPORT • 2019-2020 • RESEARCH 33