A water-dissolvable drug delivery device designed so as to reliably maintain a drug or active agent within a defined region against a mucosal surface. The shield establishes an inverse potential drop in the electrolytic fluid to overcome the resistance of a thin film of conductive metal on the wafer. In one aspect, a signal processor determines, from the signals, convection velocities of coherent structures having different length scales. 005 wt % to 41 wt %; ethoxydiglycol ranging from 0. Ions are directed at the alignment layer to provide uniformity of the pretilt angle. Adjacent successive conveyors in the acceleration and deceleration sections include a common diverting element having a speed change point at which the speeds of the adjacent successive conveyors are different in the transport direction.