Patent ID: 8454905

Claim:
A droplet actuator comprising: a first substrate comprising a first plate and a second substrate comprising a second plate separated first plate by a gap wherein the first plate comprises an electrode configuration comprising electrodes arranged for conducting one or more droplet operations, the electrode configuration comprising: a first electrode coupled to a voltage source, and first dielectric layer configuration comprising a first dielectric material layered above and along the length of the first electrode, the first dielectric material having a electrostatic energy gradient-establishing variation along the length of the electrode, wherein the droplet actuator is configured such that when voltage is applied to the first electrode, the electrostatic energy gradient is established at a surface of the first substrate along the length of the first electrode which causes a droplet to be transported along the length of the first electrode in a direction established by the energy gradient; and a second electrode coupled to a second voltage source, and a second dielectric layer configuration comprising a second dielectric material layered above the second electrode, wherein the second dielectric layer configuration differs from the first dielectric layer configuration; and wherein the second substrate lacks a dielectric material configured to establish a droplet-transporting energy gradient.