Voltammetry Under Microfluidic Control,a Flow Cell Aproach

A generic approach to the design, construction and experimental characterization of novel microelectrochemical reactors (MECR) is presented. Structurally well‐defined rectangular microchannels incorporating electrochemical sensors were fabricated using a propriety photosensitive glass and photolithographic techniques. Microelectrode sensors were produced via evaporation to yield, gold, silver or platinum bands of approximate lengths 10–50 μm. The approach outlined permits cells of dimensions in the range: height 50–100 μm, width 100–500 μm and length 1–3 cm to be accurately constructed, in single or array configurations and were characterized via a voltammetric study utilizing electrolyte solutions containing N,N,N′N′‐Tetramethyl‐1,4‐phenylenediamine. In all cases, the test cells were constructed so that the three dimensional hydrodynamic boundary layer within the cells would significantly influence the reagent transport and therefore the observed current density at the microelectrodes. The current/flow rate relationship observed was analogous to the response of the observed within the macroscopic channel flow cells, where typically the cell design is restricted to configurations where a two dimensional transport analysis can be performed.