MODIFYING ELECTRODE GEOMETRY FOR UNEQUAL DROPLET SPLITTING IN DIGITAL MICROFLUIDICS

In the present study, unequal droplet splitting is performed simply by modifying the electrode geometry: an electrode is divided into four small squares or four narrow sub-electrodes which are surrounded by regular spatial electrodes. Two possible configurations are studied for the narrower modified electrodes in which the narrow sub-electrodes are i) parallel, and ii) perpendicular to the flow direction. By actuating one (or more) sub-electrodes on one side and a spatial electrode on the other side of the droplet reproducible unequal splitting was achieved without a need for a complicated control system. In addition to reproducibility, the proposed approach offers a great deal of flexibility by splitting the droplet (or dispense a droplet) to different volumes based on the number of the actuated sub-electrodes.