Mirrored anodized dielectric for reliable electrowetting

Anodized dielectrics in a mirrored arrangement are proposed and evaluated for the parallel-plate electrowetting-on-dielectric (EWOD) configuration. As valve metal oxides with current rectifying effects, anodized dielectrics previously could only be used for EWOD under a restricted range of voltages. However, in a mirrored configuration, one side of the anodized dielectric pair is expected to always be under the correct bias to restrict current. Both the mirrored and typical configurations were tested with current leakage measurements on anodized alumina samples under cycles of negative and positive bias and a range of electric fields. The mirrored configuration was effective in limiting current leakage over all voltages applied.