SCHAEFER, Justin T; LONG, JR., John H; KOOB, Thomas J*; Univ. of California, Irvine; Vassar College; Shriners Hospital for Children, Tampa: Biomimetic vertebral columns of variable structure and mechanical properties

In order to analyze the mechanical design of vertebral columns (VCs), we built artificial VCs that mimic aspects of the morphology and mechanics of the VC of elasmobranchs. Specifically, we varied two properties of the biomimetic VCs: (1) degree of concavity of the amphicoelous vertebral centra and (2) the shear strength of the intervertebral connective tissues. We determined the biomimetic VCs� dynamic mechanical properties in lateral bending, using a three-point bending machine operating over a range of physiologic curvatures and frequencies. Both amphicoel geometry and stiffness of the intervertebral gel affect the flexural stiffness of the biomimetic VC; those with higher shear strength gels bend more like a traditional beam. The magnitude of the stiffening effect of amphocoel morphology is attenuated by higher stiffness intervertebral gels. We then compare the effects of these changes to known structural parameters of extant elasmobranch vertebral columns. This project is supported by NSF grant DBI-0442269.