Integrated microfluidic system with simultaneous emulsion generation and concentration.

Because the size, size distribution, and concentration of emulsions play an important role in most of the applications, controlled emulsion generation and effective concentration are of great interest in fundamental and applied studies. While microfluidics has been demonstrated to be able to produce emulsion drops with controlled size, size distribution, and hierarchical structures, progress of controlled generation of concentrated emulsions is limited. Here, we present an effective microfluidic emulsion generation system integrated with an orifice structure to separate aqueous droplets from the continuous oil phase, resulting in concentrated emulsion drops in situ.

Effect of insulating posts geometry on particle manipulation in insulator based dielectrophoretic devices.

In this study, the effect of the geometry of insulating posts on microparticle trapping in insulator based dielectrophoresis (iDEP) was analyzed. The motivation for this research was to study how to improve particle trapping and enrichment by modifying the shape of insulating posts used in iDEP microdevices, while keeping post spacing constant. Mixtures of inert polystyrene particles were employed for demonstrating the effects of insulator shape on particle capture and enrichment.

Dynamic microparticle manipulation with an electroosmotic flow gradient in low-frequency alternating current dielectrophoresis.

In this study, the potential of low-frequency AC insulator-based DEP (iDEP) was explored for the separation of polystyrene microparticles and yeast cells. An EOF gradient was generated by employing an asymmetrical, 20 Hz AC electrical signal in an iDEP device consisting of a microchannel with diamond-shaped insulating posts. Two types of samples were analyzed, the first sample contained three types of polystyrene particles with different diameters (0.