Chemical Engineering Seminar

Soft matter such as biological membranes, cells, tissues, and body fluids have properties that fall between those of liquids and solids. They are composed of polymers and/or particulates (liquid or solid) dispersed in a continuous phase. Biological processes and technological applications often use flow and external forces to alter the organization of soft matter at the microscale, which can  manifest  as significant changes in the material's mechanical behavior. In this talk, I will give three examples of soft matter physics at the micro-to-nanoscale that have particular relevance in biology/biotechnology.  The first part of the talk will discuss the hydrodynamics of blood in confined geometries such as the microcirculation. In this situation, the structure of blood is highly non-homogeneous, which governs phenomena such as plasma skimming and platelet margination. In the second part of the talk, I will discuss the mechanical stability of floppy vesicles under flow and how one can pose the physics of this problem in a way that is similar to droplet breakup.  In the last part of the talk, I will discuss the physics of self-entangled DNA (i.e., knotted chains), which has been recently observed in single molecule technologies and also has physical interest due to the fact that polymer entanglements can be probed at  a single-molecule level. All of these examples show that fundamental  processes  in biology/biotechnology can be described by simple physical models, and that modelling/simulation are powerful tools to investigate such phenomena.