Figure 1: Cross-sectional view (not to scale): layer sequence of the double capacitor device/module/cell. More details (e.g., on layer thicknesses) are given in the text. Since the droplet is squeezed flatly onto the dielectric layers and the lines of the gold structure are thin and narrow, there should be no phase distortion of the transmitted light wave. If either the lower/front or the upper/rear dielectric layer were missing, the set-up would constitute a single capacitor EWOD set-up.