Scanning Electrochemical Microscopy: Negative Feedback Approach Curve
This Demonstration shows how the negative feedback (insulating substrate) approach curve in scanning electrochemical microscopy (SECM) varies with the radius of the glass sheath of the ultramicroelectrode (UME).
In SECM, approach curves are used to position the UME near the substrate. The approach curve varies with the radius of the glass sheath of the UME.
: ratio of the radius of the glass sheath to the radius of the wire in the UME.
: current at the UME.
: steady-state current at the UME.
: distance from the substrate/radius of the UME.
The equation used in this Demonstration is from .
 C. Lefrou and R. Cornut, "Analytical Expressions for Quantitative Scanning Electrochemical Microscopy (SECM)," ChemPhysChem, 11(3), 2010 pp. 547–556. doi:10.1002/cphc.200900600.