Wednesday September 30, 2009
4 PM
PHO 339
| "Excitable two dimensional films: Lab on a Chip, Blood Clotting and the Physics of Nerves"
Prof. Matthias Schneider
Boston University In this talk I would like to present an overview of
the various topics I work on: i) lab-on-a-chip microfluidics, ii) the
physics of blood clotting and iii) the biophysics of membranes and nerves.
Imagine rinsing your dirty dishes and the more you scrub, the harder
everything sticks. What looks like a drama for your kitchen is an important in
our blood that helps keep you alive as you read these lines. It has long
been observed that, during blood clotting, increasing shear
rate triggers an increase in adhesion of blood platelets.
This is a fascinating phenomenon which is in clear contradiction to our daily
experience. In the first 2 parts of my presentation I will demonstrate how surface acoustic waves with amplitudes below 1nm helped resolve this ~50year old mystery.
In the final part of my talk I will change topics and point out some major flaws in membrane biology; in particular, the current model of nerve pulse propagation. The conventional model accounts only for the electrical aspect of the pulse, however, the mechanical, optic, chemical and especially thermal aspects are entirely neglected. All these properties change reversibly during the propagation and none of them are explained by the Hodgkin and Huxley model. I present an alternative view that the nerve pulse propagation is actually a 2D sound wave propagating in the membrane. Our experiments on sound propagation in lipid monolayers strongly
support this theory. More examples are given demonstrating that the physics of
2D soft films can actually explain a variety of observations without the
introduction of a “clever” protein. |
