Twin-plate electrowetting for efficient digital microfluidics

This paper describes a twin-plate electrowetting configuration for efficient digital microfluidics. In the twin-plate configuration, the electrowetting force doubles compared to a standard two plate configuration because the chord length of the effective three-phase contact line increases 2-fold with the grounded liquid droplet. For the realization of a twin-plate electrowetting device, two identical ground-type single-plate devices were attached with a gap after aligning their control electrode arrays facing each other. As a result, the twin-plate electrowetting device showed significantly faster droplet velocity than that of the two-plate device, and the required voltage to obtain the same velocity reduced down to between 70% and 80% compared to that of the two-plate device.