Patent ID: 8685344

Claim:
A droplet actuator comprising a first substrate and a second substrate, wherein: (a) the first substrate comprises one or more electrodes configured for conducting one or more droplet operations; and (b) the second substrate is arranged in relation to the first substrate and spaced from the surface of the first substrate by a distance to define a space between the first substrate and second substrate, wherein the space comprises a fluid, and wherein the distance is sufficient to contain the fluid disposed in the space; (c) the first or second substrate comprises a wettable surface defining a wettable path, wherein the wettable path is not an electrode path, and wherein the wettable path is defined from a position accessible to an exterior locus of the droplet actuator into an internal locus of the droplet actuator sufficient to: (i) cause the fluid from the external locus to flow from the external locus to the internal locus, or (ii) permit the fluid to be forced into the internal locus by a force sufficient to traverse the wettable surface without extending sufficiently beyond the internal locus; (d) the internal locus is in sufficient proximity to one or more of the electrodes such that activation of the one or more electrodes results in a droplet operation.