Residence time distributions for in-line chaotic mixers.

We investigate the distributions of residence time for in-line chaotic mixers; in particular, we consider the Kenics, the F-mixer, and the multilevel laminating mixer and also a synthetic model that mimics their behavior and allows exact mathematical calculations. We show that whatever the number of elements of mixer involved, the distribution possesses a t^{-3} tail, so that its shape is always far from Gaussian. This t^{-3} tail also invalidates the use of second-order moment and variance.

Two-dimensional numerical model of Marangoni surfers: From single swimmer to crystallization.

We numerically study the dynamics of an ensemble of Marangoni surfers in a two-dimensional and unconfined space. The swimmers are modeled as Gaussian sources of surfactant generating surface tension gradients and are shown to follow the Marangoni flow filtered at their spatial scale in the lubrication regime, an unstable situation leading to spontaneous motion as soon as the Marangoni effect is intense enough. As the system is fully unconstrained, it is possible to study the various dynamical regimes from single swimmer, two-body interaction, to the many-particles case characterized by an efficient particle dispersion.

Numerical modeling of DNA-chip hybridization with chaotic advection.

We present numerical simulations of DNA-chip hybridization, both in the "static" and "dynamical" cases. In the static case, transport of free targets is limited by molecular diffusion; in the dynamical case, an efficient mixing is achieved by chaotic advection, with a periodic protocol using pumps in a rectangular chamber. This protocol has been shown to achieve rapid and homogeneous mixing.