Medical Engineering Special Seminar

Abstract: Musculoskeletal injuries result in 65 million health care visits per year in the United States. The most common injuries are bone fractures and tendon tears or strains. In healthy musculoskeletal tissues, the body is able to decrease failure risks via complex hierarchical structures. These structures include composition gradients, energy absorbing and stress minimizing architectures, as well as multiphase composites. Disease, previous injury, and environmental factors, such as increased body acidity or muscle unloading, can modify the unique tissue structure and significantly increase failure risk and extent. To develop techniques for preventative and post-injury care it is therefore important to identify the musculoskeletal structures at multiple hierarchies and determine their mechanical roles. In addition, understanding these natural tissues can aid in the creation of new implants and devices. Alix Deymier has been investigating the role of architecture and composition from the nano- to the macro-scale on the mechanics of the musculoskeletal system via a variety of techniques including electron-energy loss spectroscopy, synchrotron x-ray diffraction, micromechanical testing, and microcomputed-tomography. She will present her work explaining how bones and tendons employ a hierarchy of structures and mechanisms to minimize failure and how these can be controlled and modified. Biography: Alix Deymier, Ph.D. is currently a postdoctoral fellow in Orthopedic Surgery at Columbia University in New York. She recently moved to Columbia University from Washington University to continue her NSBRI fellowship studying the role of mineral structure and organization on the mechanics of biological systems. She is interested in studying the role of mineral composition, structure, and organization on the mechanics of mineralized biological tissue especially in the context of metabolic acidosis. She previously obtained her Ph.D. in Materials Science and Engineering at Northwestern University where she was a NDSEG and NSF Graduate Fellow. While there she became an independent user at the Advance Photon Source at Argonne National Lab where she has used High Energy X-ray Diffraction to study load transfer as well as the mineral structure and organization in mineralized biological systems. She obtained her B.S. in Materials Science and Engineering at the University of Arizona in 2006. There, she obtained a specialization in spectroscopy and the science of cultural heritage materials.