Study of magnetohydrodynamic driven flow through LTCC channel with self-contained electrodes

Magneto-hydrodynamics (MHD) driven flow using redox species through a low temperature co-fired ceramic (LTCC) channel with screen printed gold electrodes along its sidewalls has been demonstrated. Aqueous 0.25 M K3Fe(CN)(6) with 0.25 M K4Fe(CN)(6) was used to propel 3 mu L of colored dye through an 18 mm long LTCC channel at a maximum flow rate of 0.19 mm/s with +0.3 V applied across the electrodes in the presence of 0.44 T permanent magnet. The channel width was the same as the distance between the two 16-19 mu m thick gold electrodes at 330 mu m while the depth was the same as the electrode width at 670 mu m. Fluid flow through the LTCC channel was controlled with either an electromagnet (similar to 1.78 T) or a permanent magnet (0.44 T) such that the current flow running across the gold electrodes was oriented following the right hand rule. No flow out of the opposite reservoir was observed when the current was not oriented perpendicular with the magnetic field. The electrode life span in the LTCC channel using 0.25 M K3Fe(CN)(6) with 0.25 M K4Fe(CN)(6) decreased at a rate of 0.14% per hour over 68 h of cyclic voltammetry and chronoamperometry. We demonstrated that the LTCC channel flow rate is affected by the nature and concentration of the redox species, solution composition, the applied potential across the electrodes, and the intensity of the magnetic field. Redox MHD driven flow is useful in the development of lab-on-a-chip for micro-total analysis systems. (c) 2006 Elsevier B.V. All rights reserved.