College of Arts and Sciences Publications and Scholarship

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.

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

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

Download

Share

COinS