Steady-state voltammetry using microwire electrodes under microfluidic control

The development and application of a new hydrodynamic electrochemical devic e is described. This novel technique is based on a microwire electrode with approximate dimensions of 25 mu m, sited centrally within a rectangular du ct (of 800 mu m height and 0.05-0.02 m width), subjected to fluid flow unde r well-defined mass transport conditions. Finite element simulations are pr esented to model the solution velocity profiles within the cell and around the microwire electrode. The results of these calculations were employed to characterize the concentration distribution of a reactant within the cell, which is undergoing a transport-limited reaction at the electrode/solution interface. Experimental studies using the new technique were performed usi ng aqueous and organic solutions containing ferrocene and potassium ferrocy anide to establish the variation of electrolysis current as a function of t he solution flow rate. The experimental results are compared to those predi cted numerically and good agreement is noted.