Compressed Sensing Image Reconstruction of Scanning
Electrochemical Microscopy Measurements Carried Out at Ultrahigh Scan
Speeds Using Continuous Line Probes
posted on 2021-09-08, 21:33authored byAnna E. Dorfi, Jingkai Yan, John Wright, Daniel V. Esposito
Previous
studies on scanning electrochemical microscopy (SECM)
imaging with nonlocal continuous line probes (CLPs) have demonstrated
the ability to increase areal imaging rates by an order of magnitude
compared to SECM based on conventional ultramicroelectrode (UME) disk
electrodes. Increasing the linear scan speed of the CLP during imaging
presents an opportunity to increase imaging rates even further but
results in a significant deterioration in image quality due to transport
processes in the liquid electrolyte. Here, we show that compressed
sensing (CS) postprocessing can be successfully applied to CLP-based
SECM measurements to reconstruct images with minimal distortion at
probe scan rates greatly exceeding the conventional SECM ″speed
limit″. By systematically evaluating the image quality of images
generated by adaptable postprocessing CS methods for CLP-SECM data
collected at varying scan rates, this work establishes a new upper
bound for CLP scan rates. While conventional SECM imaging typically
uses probe scan speeds characterized by Péclet numbers (Pe) < 1, this study shows that CS postprocessing methods
can allow for an accurate image reconstruction for Pe approaching 5, corresponding to an order of magnitude increase in
the maximum probe scan speed. This upper limit corresponds to the
onset of chaotic convective flows within the electrolyte for the probes
investigated in this work, highlighting the importance of considering
hydrodynamics in the design of fast-scanning probes.