203. ARMADILLO ARMOR: MECHANICAL TESTING AND MICRO-STRUCTURAL EVALUATION
Research Institute Affiliation: Graduate Program in Materials Science and Engineering
Faculty Advisor(s): Marc A. Meyers
Name: Irene Hsu Chen
Grad Year: 2012
The armadillo has a unique protective bony armor, called the osteoderm, which confers to its shell-like skin with distinctive mechanical properties. The top layer of the shell is made out of a dark-brownish keratin layer, arranging in a bimodal random pattern. Beneath the keratin layer, the osteoderm consists of hexagonal and triangular tiles with both tiles having a composition that is the same as bone (mainly collagen type I fibers and hydroxyapatite minerals). The tiles are connected by non-mineralized collagen fibers, called Sharpey fibers. The hierarchical structure of armadillo osteoderm is characterized using optical microscopy, SEM, and AFM. Various mechanical tests (tensile, shear, impact, and flexural) are performed and fracture surface is examined under SEM. Toughening mechanisms will be discussed and compared with other mineralized tissues. This research is supported by NSF Grant (Ceramics and Biomaterials Program) 1006931.