• [2012-08-07]

  Date posted: July 16, 2012 From Red Cells to Skiing to Soft Lubrication

Title：<span verdana','sans-serif';="" mso-bidi-font-family:="" 宋体"="" lang="EN-US"> From Red Cells to Skiing to Soft

<span verdana','sans-serif';="" mso-bidi-font-family:="" 宋体"="" lang="EN-US"> 

Speaker：Qianhong Wu, Ph.D.  Associate Professor

Director, Cellular Biomechanics and Sports Science Laboratory Department of Mechanical Engineering Villanova University, USA

Host：Chunyang Xiong

Time：9:00 am

Date：July 17, 2012

Venue：Conference Room 212, Building No.1, Engineering College

  Abstract：Biological scientists have wondered, since the motion of red cells was first observed in capillaries, how a red cell, with an 8µm diameter, can move with so little friction in tightly fitting microvessels, only 5-6 µm in diameter, and survive 105 passages through microcirculation during a typical lifetime of 120 days without being damaged or undergoing hemolysis. Recent studies (Feng and Weinbaum, JFM, 2000; Weinbaum et al., PNAS, 2003; Wu et al., PRL, 2004) attributed this frictionless motion to the dramatically enhanced hydrodynamic lifting force generated inside the endothelial glycocalyx layer (EGL), a soft porous layer that covers the inner surfaces of our capillaries, as a red blood cell glides over it. Lift generation inside highly compressible porous media is a new concept for porous media flow. In this talk, a systematic study of this concept is presented. Its diverse applications, from red cells moving in a tightly fitting capillary, to human skiing or snowboarding, to a next generation high speed train that glides on a soft porous track made of goose down pillow will be discussed as examples. These applications are chosen for their novelty, but the basic concepts could have important application in the design of soft porous bearings with greatly increased lubrication pressures and long life.