Figure 7. Drop behind bars.

(a,b) Conducting beads on the surface of a silicone drop with a radius of about 1 mm embedded in castor oil: the beads attract and form chains, resulting in a colloidal bar armour. The drop now has a prolate shape, owing to the increase in electric conductive from the chains, which short-circuit the drop and supress the free surface charges inducing the Taylor–Melcher EHD flow. (c,d) At lower bead concentration, the chains do not span the entire drop, and the drop is oblate, indicating presence of Taylor–Melcher EHD flow. The arrows and crosses indicate the direction of the E-field.