Washing in two phase flow

The rapidly growing interdisciplinary field of two-phase microfluidics combines soft matter physics, biochemistry and microsystems engineering. With its micro compartments surrounded by an immiscible carrier phase, it offers applications that range from rapid analytical systems or the synthesis of advanced materials to biological assays for living organisms.
In this thesis, two-phase microfluidics and its limits as an assay-platform for diagnostics and therapeutics are examined. In the first part, their use as an assay platform in liquid-liquid phase systems is investigated and a solution for the fundamental extraction and washing problem of this system is proposed by structuring the surface wettability and improving the assay performance of the fluidic system. The second part investigated the production of gel phases as carrier materials in this type of microfluidics. The introduction of a photo crosslinking chemistry alternative to standard processes enabled the gelation and simultaneous bio functionalization of the gel phase. The use of these bio functional gel carrier materials as hydrogel particles is demonstrated in a typical particle-based assay system as well as in a novel fluidic system based on hydrogel particles. In this system, the advantages of the droplet-based assays are combined with those of the hydrogel particles and thus a solution for the elementary washing problem is offered.