Liquid flow between hydrodynamicaly interacting particles in confined systems

Particle suspensions in confined geometries are greatly complex systems since they introduce a high degree of complexity into the otherwise linear Stokes flows. Very recently, new mechanisms of instability have been identified in simulations in confined shear-flows of non-Brownian dilute particle solutions (Zurita-Gotor et al., J. Fluid Mech. 592, 2007, and Phys. Rev. Lett. 108, 2012). In this study we will focused on particle pairs interacting with walls, which requires the use of micro-confined systems. By the use of Astigmatism-PTV on particle solutions with different fluorescent characteristics, we will solve both the non-Brownian interacting particle trajectories and the flow around them in order to elucidate the details of the hydrodynamic particle-particle interactions.