Chang and coworkers have further demonstrated that increased surface area of a permselective membrane leads to smaller vortices due to a decrease in the current density. Another recent approach is to microstructure the surface of the ion selective membrane. In this paper, we describe out-of-plane fICP, in which electrokinetic enrichment of charged analytes is driven by a 3-dimensional (3D) flow-through electrode comprising a bed of metallic beads. This approach combines the design principles from the aforementioned studies to achieve stable, high-throughput preconcentration of charged analytes. Specifically, we demonstrate that a flow-through 3D electrode, comprising a bed of Ag-coated microbeads overlying an Au microband ('Ag/Au', Scheme 2c), generates an IDZ, leading to an electric field gradient distributed across the entire cross section of a microchannel. In this system, IDZ formation at the 3D electrode is driven by neutralization of a buffer cation by electrochemically generated OH -. The formation of small, non-disruptive fluid vortices is supported by the microstructure of this bead bed and its large surface area, which supports decreased current density. To further restrict vortex growth, we employ a secondary bead bed comprised of polystyrene carboxylate (PSC) beads, located upstream of the 3D electrode ('PSC/Ag/Au', Scheme 2d). This secondary bed geometrically confines fluid laminae and enhances surface conduction of ions from the bulk solution to the electrode. We compare these device designs to one having a conventional planar Au electrode ('Au', Scheme 2b). We first evaluate the enrichment of a small molecule fluorophore and a dye-linked protein, at a planar Au electrode, and verify the presence of three distinct regimes in the CVC, thereby confirming the fICP mechanism. Second, the rate and morphology of IDZ growth, current transients, and the shape of the CVCs are compared for the Au, Ag/Au, and PSC/Ag/Au devices.