| Title: |
Electrochemical stability and neural recording with sputtered ruthenium oxide electrodes subchronically in rat motor cortex |
| Authors: |
Abbott, Justin R; Jeakle, Eleanor N; Wu, Yupeng; Smith, Thomas J; Geramifard, Negar; Chakraborty, Bitan; Khajehzadeh, Mahasty; Dhananjayan, Sahana; Hernandez-Reynoso, Ana G; Pancrazio, Joseph J; Cogan, Stuart F |
| Contributors: |
National Institute of Neurological Disorders and Stroke |
| Source: |
Journal of Neural Engineering ; volume 22, issue 4, page 046019 ; ISSN 1741-2560 1741-2552 |
| Publisher Information: |
IOP Publishing |
| Publication Year: |
2025 |
| Description: |
Objective . To investigate sputtered ruthenium oxide (RuO x ) as a low impedance coating for recording neural activity with intracortical microelectrode arrays (MEAs). Approach. RuO x was sputtered onto active sites of amorphous silicon carbide (a-SiC) MEAs and evaluated electrochemically and as a recording electrode coating over 6 weeks in rat motor cortex. The RuO x was 250 nm thick with a 200 μ m 2 geometric electrode surface area. We performed weekly electrochemical impedance spectroscopy and cyclic voltammetry (CV) measurements and single-unit action potential recordings. Main results. From 1 to 6 weeks post-implantation, we observed that median 1 kHz impedance decreased from 1.06 MΩ to 0.68 MΩ, median 1 Hz impedance decreased from 24.5 MΩ to 20.7 MΩ, and median 30 kHz impedance remained constant at 0.19 MΩ. Linear regression fits indicated that the 1 kHz and 1 Hz impedance exhibited small decreases whereas the 30 kHz impedance values had no discernible trend. The CV-based charge storage capacity (CSC c ) also exhibited consistency over time. The median CSC c at 50 mV s −1 was 24.3 mC cm −2 on week 1 and 20.1 mC cm −2 at week 6. At 50 000 mV s −1 sweep rate, the median CSC c was 2.4 mC cm −2 at 1 week and 2.8 mC cm −2 at 6 weeks. Regressions for both sweep rates exhibited no significant slope deviations from zero. Neural recordings spanning 6 weeks demonstrated consistent single unit action potential with a 75% single unit active-electrode-yield over 6 weeks. Median V pp values on week 1 were 97.6 µ V and 105 µ V by week 6. The median and quartile signal-to-noise ratio (SNR) was 12 at week 1 and 12 at week 6. There were no deviations from zero on the regressions for both V pp and SNR. Significance. The findings suggest that RuO x is stable over subchronic implantation periods. Future research will explore long-term chronic performance and broader applications of RuO x in neural interface devices. |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| DOI: |
10.1088/1741-2552/adee49 |
| DOI: |
10.1088/1741-2552/adee49/pdf |
| Availability: |
https://doi.org/10.1088/1741-2552/adee49; https://iopscience.iop.org/article/10.1088/1741-2552/adee49; https://iopscience.iop.org/article/10.1088/1741-2552/adee49/pdf |
| Rights: |
https://creativecommons.org/licenses/by/4.0/ ; https://iopscience.iop.org/info/page/text-and-data-mining |
| Accession Number: |
edsbas.7F13CE78 |
| Database: |
BASE |