Construction and behaviour of ultramicroelectrodes: Investigations of Novel Electrochemical Systems

Microelectrodes can be made using a variety of techniques including: (1) sealing of fine wires (e. g. Pt-Woolaston wires having radii down to 0. 3 mu m) into glass and exposing the circular end sections, (ii) drawing down of fine metal wires in glass shields, (iii) evaporation of metals, (iv) etching of metals covered by resists, (v) deposition of metals (e. g. mercury droplets of radii less than 10 nm) as single centres onto microelectrode substrates or as an assembly of small droplets onto macroscopic electrodes. These techniques are reviewed; the construction of a Pt-Woolaston electrode is illustrated.