Patent ID: 8394249

Claim:
A method for splitting a starting droplet into two or more droplets, comprising the steps of: (a) providing a starting droplet on a surface of a first substrate, the substrate comprising an array of drive electrodes, wherein the drive electrode array comprises at least three drive electrodes comprising a first outer drive electrode, a medial drive electrode adjacent to the first outer drive electrode, and a second outer drive electrode adjacent to the medial drive electrode, and the starting droplet is initially disposed on at least one of the three drive electrodes and is adjacent to at least one other of the three drive electrodes; (b) biasing each of the three drive electrodes to a first voltage to position the starting droplet across the three drive electrodes; and (c) biasing the medial drive electrode to a second voltage different from the first voltage to split the starting droplet into first and second split droplets, whereby the first split droplet is formed on the first outer drive electrode and the second split droplet is formed on the second outer drive electrode; and (d) wherein the substrate further comprises a dedicated grounded electrode disposed in at least substantially co-planar relation to the drive electrode array, wherein the grounded electrode is electrically and physically distinct from the drive electrode array, and the droplet overlaps the grounded electrode.