Professor W. Gregory Sawyer
University of Florida
Department of Mechanical and Aerospace Engineering
231 MAE-A P.O. Box 116250
Gainesville, FL 32611
Invited Speaker: Professor W. Gregory Sawyer, University of Florida
Presentation: "Tribology in Biomedicine"
W. Gregory Sawyer is the N.C. Ebaugh Chair and Professor in the Departments of Mechanical and Aerospace Engineering, and Materials Science and Engineering, and Biomedical Engineering. He is also a Distinguished Teaching Scholar at the University of Florida. Greg has published over 150 journal papers, and has over 7000 citations. His research interests have led to many adventures, from operating experiments (remotely) in space on the International Space Station to conducting experiments in vivo
on a cornea.
The human body is an extremely complex moving mechanical assembly of living tissue, with a myriad of contacting interfaces that enable biological function and healthy life from a blink to a heartbeat. By-and-large engineering to date has provided metal and plastic replacement alternatives for biological systems in need of repair. Today there is substantial enthusiasm for regenerative medicine, gene therapy, and other biological alternatives to the current state-of-the-art in medicine. These new biological approaches possess numerous tribological complexities that are often associated with system-level biological function. Exciting advances over the past decade enabled tribologists the opportunity to consider macroscopic interfaces in atomic and molecular terms. These developments have entailed ultra-low force measurements that are sensitive to the rupture of single chemical bonds and friction measurements spatially resolved to the level of individual atoms. The opportunity now exists to address the role of tribological action within biological systems, seeking to characterize, understand, and exploit cellular interfaces and interactions on a molecular scale.
Soft biological materials are often used in applications that involve contact and relative motion. The cornea is prime example of a natural tribological system. The cornea is the optical portal to the visual system and it forms a dense, transparent connective tissue barrier that protects the eye. The cornea experiences approximately 8 million blinks per year. Lubrication and maintenance of the proper cellular and extracellular matrix composition of the cornea is essential to its function. The external surface of the cornea is lined with a thin epithelium composed of 5-6 layers of fibroblastic cells that form a protective layer over the corneal stroma. These cells rapidly regenerate the epithelium following injury. This talk with present some new experiments that have measured the friction on living corneal epithelial cells under contact.