Cation exchange membrane integrated into a microfluidic device

We have developed an electrochemical micro-system with embedded Ralex (R) CM PES membrane which separates two electrolytes of the same composition and concentration. Gold sensing micro-electrodes were integrated into the micro-system. The precise control of the hydrodynamic conditions - uniform flow of the solutions, uniform electric current distribution in micro-channels, spatial resolution of the measurement (small dimensions of the electrodes) and the precise positioning of the measuring elements represent the main advantages of the micro-scale arrangement. Polarization curves of the fabricated micro-system were measured to verify the functionality of the system. Dependencies of the key parameter, limiting current density, on several parameters as hydrodynamic conditions and electrolyte concentration have been also studied. Chronopotentiometric curves of the constructed micro-system were measured and evaluated. (C) 2009 Elsevier B.V. All rights reserved.