CONVECTIVE DIFFUSION TO A MICRODISK SENSOR SUBJECT TO UNIFORM SHEAR-FLOW

When an electrode reacts with a chemical species in a fluid, a current is generated that can be measured to determine the amount of the reac tant in the fluid. For sufficiently small electrodes, the measuring pr ocess is, to good approximation, insensitive to fluid motion, as the m icroelectrode is housed within a nearly stagnant layer of fluid. In th is work we elucidate the effect of convection on the response of a mic rosensor electrode. The transient convective-diffusion equation that d escribes mass transport of the chemical species to the electrode conta ins a single dimensionless group, the Peclet number, and solutions are found on a three-dimensional domain using a modified version of oblat e spheroidal coordinates.