Applications of microelectrodes in impedance spectroscopy

Using a simple method for manufacturing of micro-tips, numerous microelectrodes with reasonably small electroactive area were produced by insulating the micro-tips into glass capillaries. Microelectrode characterisation was carried out with steady state diffusion limited current measurements in acidic FeCl 3 solution. The microelectrodes were used for different purposes, the simplest of which was measuring the impedance in the region of a small conductive area placed in an insulating surrounding. Other measurements were carried out by generating impedance profiles in different electrolytes, as a microelectrode approached a conversion-coated metal surface, in order to gain information about the properties of the coating.