Electrochemical and mechanical performance of reduced graphene oxide, conductive hydrogel, and electrodeposited Pt-Ir coated electrodes : an active in vitro study

OBJECTIVE: To systematically compare the in vitro electrochemical and mechanical properties of several electrode coatings that have been reported to increase the efficacy of medical bionics devices by increasing the amount of charge that can be delivered safely to the target neural tissue.

APPROACH: Smooth platinum (Pt) ring and disc electrodes were coated with reduced graphene oxide, conductive hydrogel, or electrodeposited Pt-Ir. Electrodes with coatings were compared with uncoated smooth Pt electrodes before and after an in vitro accelerated aging protocol. The various coatings were compared mechanically using the adhesion-by-tape test. Electrodes were stimulated in saline for 24 hours/day 7 days/week for 21 d at 85 °C (1.6-year equivalence) at a constant charge density of 200 µC/cm2/phase. Electrodes were graded on surface corrosion and trace analysis of Pt in the electrolyte after aging. Electrochemical measurements performed before, during, and after aging included electrochemical impedance spectroscopy, cyclic voltammetry, and charge injection limit and impedance from voltage transient recordings.

MAIN RESULTS: All three coatings adhered well to smooth Pt and exhibited electrochemical advantage over smooth Pt electrodes prior to aging. After aging, graphene coated electrodes displayed a stimulation-induced increase in impedance and reduction in the charge injection limit (p   <  0.001), alongside extensive corrosion and release of Pt into the electrolyte. In contrast, both conductive hydrogel and Pt-Ir coated electrodes had smaller impedances and larger charge injection limits than smooth Pt electrodes (p   <  0.001) following aging regardless of the stimulus level and with little evidence of corrosion or Pt dissolution.

SIGNIFICANCE: This study rigorously tested the mechanical and electrochemical performance of electrode coatings in vitro and provided suitable candidates for future in vivo testing.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:17

Enthalten in:

Journal of neural engineering - 17(2019), 1 vom: 23. Dez., Seite 016015

Sprache:

Englisch

Beteiligte Personen:

Dalrymple, Ashley N [VerfasserIn]
Huynh, Mario [VerfasserIn]
Robles, Ulises Aregueta [VerfasserIn]
Marroquin, Jason B [VerfasserIn]
Lee, Curtis D [VerfasserIn]
Petrossians, Artin [VerfasserIn]
Whalen, John J [VerfasserIn]
Li, Dan [VerfasserIn]
Parkington, Helena C [VerfasserIn]
Forsythe, John S [VerfasserIn]
Green, Rylie A [VerfasserIn]
Poole-Warren, Laura A [VerfasserIn]
Shepherd, Robert K [VerfasserIn]
Fallon, James B [VerfasserIn]

Links:

Volltext

Themen:

49DFR088MY
7782-42-5
Coated Materials, Biocompatible
Graphene oxide
Graphite
Hydrogels
Journal Article
Platinum
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 08.10.2020

Date Revised 08.10.2020

published: Electronic

Citation Status MEDLINE

doi:

10.1088/1741-2552/ab5163

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM302572589