Nano- & Microfluidics:

In the current funding period, we continue and extend our analysis of the dynamical behaviour of microcapsules in shear flow. We have developed a numerical code based on spectral methods to solve the full nonlinear dynamics of elastic microcapsules. With the help of this code we study flow induced transitions (like the transition from tanktreading to tumbling motion or the more recently predicted intermittent behaviour) at larger deformations. Moreover, we study the effect of thermal fluctuations on a fluid vesicle in shear flow using analytic methods.

In a second line of investigations, we will study the effect of short scale membrane roughness on the dynamics. In particular, we plan to map the flow around the rough membrane onto effective boundary conditions for flow around a smooth membrane. We will then investigate the mutual interaction between the rough membrane and the flow. We will allow the roughness to be either statically imposed (like in a ripple phase), Flow-induced (like in wrinkling) or thermally generated (for fluid membranes). For the latter case, we will develop appropriate averaging procedures based on a variational formulation of the Stokes problem and its stochastic extension as a field theory.

More information about the group working on this project