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The Scanning Vibrating Electrode Technique

A. C. Bastos

CICECO / Department of Ceramics and Glass Engineering, University ofAveiro, Portugal

The Scanning Vibrating Electrode Technique - SVET in the abbreviated form - uses a vibrating microelectrode to measure the electrical field in solution associated to the ionic fluxes originated by electrochemical reactions at corroding metal surfaces or by metabolic processes in biological cells and tissues. The results are usually report-ed as maps of ionic current densities Crossing the piane of measurement.

For long reference electrodes have been applied in the corrosion field to map po-tential distribution in solution [1-3]. Vibrating electrodes, however, are much morę sensitive and were developed by biologists to study ionic fluxes in biological Systems [4-7], being introduced to the corrosion field in the 1980's [8-10].

This presentation gives a brief introduction to the SVET technique and is divided in 4 moments: (1) the measurement of potential and current in solution and the func-tioning of SVET; (2) an historical overview of SVET; (3) selected results in corrosion and biology; (4) going further, the coupling of SVET with other techniques. References

1.    U.R. Evans, Metal Ind. 29 (1926) 481

2.    W. Jaenicke, K. F. Bonhoefer, Z. Phys. Chemie A193 (1944) 301 3.1. R. Copson, Trans. Electrochem. Soc. 84 (1960) 29

4.    O. Bluh, B. Scott, Rev. Sci. Inst. 10 (1950) 867

5.    W. P. Davies, Fed. Proc. 25, Abstract 801 (1966) 332

6.    L. F. Jaffe, R. Nucitelli, J. Celi Biology 63 (1974) 269

7.    C. Scheffey, Rev. Sci. Instrum. 59 (1988) 787

8.    H. S. Isaacs, Y. Ishikawa, Applications of the Vibrating Probe to Localized Current Measure-ments, in Electrochemical Techniques for Corrosion Enginnering, R. Baboian (Ed.), NACE, Houston, 1986

9.    H. S. Isaacs, Corros. Sci. 28 (1988) 547

10.    H. S. Isaacs, A. Shipley, A. J. Davenport, J. Electrochem. Soc, 138 (1991) 390