Parallel Transportation of Droplets in a Multilayer Device by MEWOD

An electrowetting-based multilayer device capable of concurrent manipulation of stacked multiple droplets along the same trajectory was demonstrated. A dielectric sheet was placed between a pair of parallel glass plates with dielectric coated ITO electrodes and divided the space into two fluidic channels. Two droplets were dispensed in the two isolated channels above and beneath the dielectric sheet. When applying a voltage between the top blank ITO electrode and one of the bottom patterned ITO electrodes, electrowetting occurred on the powered dielectric-coated ITO electrodes (EWOD) as well as the two sides of the dielectric sheet (MEWOD). As a result, both of the droplets were successfully pumped onto the energized electrode. The MEWOD phenomenon was studied, and the proposed concept would be expanded to manipulate more than two droplets without increasing the complicity of the device fabrication and the electric circuit.