Influence of Geometry on the Electrochemical Response of Carbon Interdigitated Microelectrodes

Abstract

Electrodes of small dimensions, commonly referred to as microelectrodes, are attracting attention for applications that include sensors, detectors and microelectromechanical systems (MEMS). [1][2][3] These electrodes are fabricated in a variety of structures, different geometric arrangements, and of different compositions. Semiconductor processing techniques that involve photolithography, reactive ion etching, vapor deposition, etc. are suitable methods for fabricating microelectrodes. Dimensions of <10 m for the width and separation of microelectrodes are feasible by these techniques.Microelectrodes are being actively considered for electrochemical applications. 4,5 In particular, microelectrodes have attracted attention for use in chemical analysis. [6][7][8][9][10][11][12][13] Both two-dimensional microdisk 6,9,10,13,14-16 and one-dimensional band 7,8,[17][18][19] electrodes are under investigation. An advantage of these microelectrode systems is the sensitivity to detection of low concentrations of electroactive species.Microelectrodes exhibit a different electrochemical response to redox species in solution than large planar electrodes. Cyclic voltammetry of redox species at large planar electrodes shows currentpotential profiles that are indicative of current peaks during the anodic and cathodic potential sweeps. On the other hand, cyclic voltammetry of microelectrodes reveals the presence of a current plateau rather than a current peak when the redox species undergoes electrochemical reaction. Because of their small dimensions, spherical diffusion occurs at the microelectrodes rather than linear diffusion.The use of photolithography and patterned photoresists offer an interesting option for design and fabrication of different electrode structures of microdimensions. Kostecki et al. 20 demonstrated the electrochemical behavior of carbon interdigitated array electrodes (IDAEs) fabricated from carbonizing photoresist that was spin coated on an Si wafer and patterned in an array by photolithography. Extension of the electrochemical studies of carbon IDAEs is the subject of this paper, and in particular, we report results obtained with carbon films produced from different photoresists pyrolized at 700 and 1000ЊC and with another carbon IDAE array of different geometry.

Electrooxidation of C1 to C3 alcohols with Pt and Pt–Ru sputter deposited interdigitated array electrodes

“…Interdigitated array electrodes, which are fabricated by photolithographic techniques with very narrow gaps of about several tenth micro-meters between the electrodes, are useful for the characterization of electrochemical reactions [27,28]. A previous work focused on the reaction characteristics in methanol oxidation with a Pt sputtered 10 m gap between interdigitated array electrodes [28].…”

Nanoscale fabrication and modification of selected battery materials

“…A more detailed description of the electrochemical cell and experimental conditions is presented by Kostecki et al [2,4].…”

“…Because carbons are available in a wide variety of morphologies and crystallographic structures, there are many opportunities to use carbon in battery applications. One approach that we are exploring is the use of semiconductor-processing techniques that involve photolithography to pattern photoresists and subsequent pyrolysis to form carbon microstructures that function as microelectrodes [1][2][3][4]. In this paper, we describe the status of the fabrication of carbon microelectrodes obtained by pyrolysis of photoresist and characterization of the carbons by surface-sensitive techniques and electrochemical analysis by cyclic voltammetry.…”

Pyrolyzed Photoresist Carbon Electrodes for Microchip Electrophoresis with Dual-Electrode Amperometric Detection

“…In addition, these electrodes were shown to only weakly absorb methylene blue, which is known to physisorb strongly to most carbon surfaces [28]. Lastly, the use of interdigitated PFF electrodes for cyclic voltammetric measurements was investigated by Kostecki et al [27].…”