"For decades this rather amazing complex biocomposite material has baffled scientists as to how it exhibits such outstanding compressive stiffness, toughness, strength, resiliency, and shock absorption, and why and how these properties degrade with age and certain debilitating diseases," said Christine Ortiz, an assistant professor in the Department of Materials Science and Engineering.
The new work, to be reported in the journal Macromolecules, will aid studies to that end. It represents the first direct measurements of the nanoscale forces between a surface of real "bristle" cartilage molecules and a tiny probe tip of known geometry and chemistry. The results give insights into bristle behavior and structure.
"Currently we are expanding this project to look at the forces between the other load-bearing molecules of cartilage to help understand the role of each," Ortiz said. The basic techniques used in the work, she noted, are also being used by the same team to explore systems such as industrially important polymers, drug particles, bone and bone implant materials, and interactions between membrane proteins and foreign bodies.
Ortiz's MIT coauthors on the paper are Alan Grodzinsky, a professor with a dual appointment in the Biological Engineering Division and the Department of Electrical Engineering and Computer Science (EECS) and a joint appointment in the Department of Mechanical Engineering, and graduate students Joonil Seog of mechanical engineering and Delphine Dean of EECS. Their coauthors from
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Contact: Elizabeth Thomson
thomson@mit.edu
617-258-5402
Massachusetts Institute of Technology
11-Jun-2002