FLEXIBLE ULTRAMICROLINE ELECTRODES

Flexible ultramicroline electrodes have been made from a variety of materials, including Au, Pt, Ir, and C. The thickness of these materials ranges from 3.5 nm (approximately 13 atoms thick) to 700 nm. The smallest electrodes are comparable to the smallest rigid line electrodes produced by other techniques. The electrode material is sandwiched between flexible polymer supports, and the bottom is cut with a scalpel to produce the working face of the ultramicroline electrode. The special method of attaching the films to the polymer support allows a high degree of electrode flexibility without causing fractures and concomitant increases in resistance and altered electrode characteristics. The flexibility of these electrodes offers the potential for easy fabrication of a variety of electrode configurations, including spirals, rings, concentric rings, linear arrays, and ring‐disc electrodes. Examples of the electrochemical behavior of ultramicroline and ultramicroring electrodes are described and are similar to those of rigid ultramicroelectrodes that are produced using other technologies. The carbon ultramicroline electrodes are somewhat more susceptible to mechanical damage than the metallic electrodes when they are flexed, and the resistivity increases on bending, thus indicating some fracturing of the film. Nonetheless, they can still be bent into various geometries and are electrochemically useful. Copyright © 1990 VCH Publishers, Inc.