CAS Publications
ORCID
David O. Wipf: https://orcid.org/0000-0003-2365-1175
Mario A. Alpuche-Aviles: https://orcid.org/0000-0003-2615-4115
Abstract
A new constant-distance imaging method based on the relationship between tip impedance and tip-substrate separation has been developed for the scanning electrochemical microscope (SECM). The tip impedance is monitored by application of a high frequency ac voltage bias between the tip and auxiliary electrode. The high frequency ac current is easily separated from the dc level faradaic electrochemistry with a simple RC filter, which allows impedance measurements during feedback or generation/collection experiments. By employing a piezo-based feedback controller we are able to maintain the impedance at a constant value and, thus, maintain a constant tip-substrate separation. Application of the method to feedback and generation/collection experiments with tip electrodes as small as 2 mm is presented.
Publication Date
2001
College
College of Arts and Sciences
Department
Department of Chemistry
Keywords
Scanning probe microscopy, SECM, impedance, position control, electrochemistry, ultramicroelectrode
Disciplines
Analytical Chemistry
Recommended Citation
Wipf, David O. and Apuche-Avlles, Mario A., "Impedance Feedback Control for Scanning Electrochemical Microscopy" (2001). CAS Publications. 29.
https://scholarsjunction.msstate.edu/cas-publications/29
Comments
This is a preprint of work now published as
Impedance Feedback Control for Scanning Electrochemical Microscopy Mario A. Alpuche-Aviles and David O. Wipf, Analytical Chemistry 2001 73, 4873-4881. https://dx.doi.org/10.1021/ac010581q