Many animals possess dermal armor, which acts primarily as protection against predators. We illustrate this through examples from both our research and the literature: alligator, fish (alligator gar, arapaima, and Senegal bichir), armadillo, leatherback turtle, and a lizard, the Gila monster. The dermal armor in these animals is flexible and has a hierarchical structure with collagen fibers joining mineralized units (scales, tiles, or plates). This combination significantly increases the strength and flexibility in comparison with a simple monolithic mineral composite or rigid dermal armor. This dermal armor is being studied for future bioinspired armor applications providing increased mobility.
KeywordsCollagen Fiber Collagen Fibril External Layer Internal Layer Fish Scale
We thank Gaspar Ritter, owner of the Kuryala Lodge, Araguaia River, Brazil, for the arapaima scales, and Diane Ulery Natural Art Jewelry, Louisiana, for the alligator gar scales. This research is funded by the National Science Foundation, Division of Materials Research, Grant #1006931, and by the UC Lab Fees Research Program No. 09-LR-06-118456-MEYM. Special gratitude goes to Mr. Yenshan Lin who prepared the arapaimas specimens and Professor Po-Yu Chen, National Tsing Hua University, Taiwan, ROC, for helpful discussions. We thank Prof. C. Ortiz for authorizing the use of Fig. 7.
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