Droplet transition principle app
Instead of a laminar parallel flow, multiphase (e.g., double emulsion) droplet flows in a microchannel can be used and phase separation can be achieved by breakup of a multiphase droplet. A laminar flow helps to maintain a stable interface between two liquids, however, it limits the interfacial area, thus hinders mass transfer rate, which poses the major challenge in these technologies. Most of these methods utilize laminar parallel flows in microchannels. Until now, phase separation has been achieved by adding surfactant, by using structured microchannels with differing wettability, by surface treatments or by combining several techniques. Following the solvent extraction, the two immiscible phases are separated in order to retrieve the extracted substance. aqueous two-phase system), oil or ionic liquid. Typically, one is aqueous phase and the other often comprise of organic solvent, another immiscible aqueous phase (e.g. These processes utilize the interface between two immiscible liquids. Liquid–liquid micro extraction processes have been performed for separation and partitioning of cells, proteins, molecules, and ions in various applications. In recent years, solvent extraction and partitioning processes have been miniaturized into lab-on-a-chip devices due to their favorable position in terms of better mass transfer efficiency, higher specific interfacial area, and the lower consumption of reagents compared to classical macroscale approaches. Less than 2% of residue was achieved by both methods, which is almost 90% improvement compared to the phase separation by the conventional droplet splitting technique in EWOD DMF platform, where the residue percentage can go up to 20%. In the second method, while keeping the applied voltages same on both sides, we tested the phase separation performance by varying the actuation schemes. In the first method, we applied different EWOD operation voltages on two phases to maintain equal capillary numbers during phase separation.
In this study, we propose two different ways to control the deformation of the phases. The larger capillary number of the neck forming phase is associated with the larger amount of deformation as well as more residue.
It was conceived that the residue formation can be controlled by controlling the deformation of the phases.
Phase separation performance in terms of percentage residue of one phase into another phase has been quantified. Electrowetting-on-dielectric (EWOD) actuation has been used to mechanically separate the phases. This study reports the first comprehensive investigation of separation of the immiscible phases of multiphase droplets in digital microfluidics (DMF) platform.