CCB Colloquium: “Short Stories of Transport Processes and Molecular Biology” (Howard A. Stone, Ph.D.)

Speaker: Howard A. Stone
Donald R. Dixon ’69 and Elizabeth W. Dixon Professor in Mechanical and Aerospace Engineering, Princeton University.

Title: Short Stories of Transport Processes and Molecular Biology

I will provide a glimpse of recent projects in my research group that involve fluid dynamics and transport processes as they potentially impact some biological problems. In particular, I will present results of bacterial growth in a partially saturated porous media, where production of a biosurfactant leads to liquid flow in corners, which helps to rationalize our results on bacterial spreading (even for non-motile bacteria)1. Second, I will discuss our observations and modeling of liquid-liquid phase separation in branching nucleation that accompanies spindle formation, which is a precursor to cell division2. Finally, in the time remaining I will give a short overview of the directed motion of colloid particles owing to chemical gradients3, which is known as diffusiophoresis. Although discovered many decades ago, my experience is that most researchers are unaware of the phenomenon, yet the concepts seem broadly applicable to out-of-equilibrium colloidal systems. Both experiments and theory will be shown, including the effects of ion valence and background electrolyte, and possible biological implications will be suggested.