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Insights into the Electron Transfer Kinetics, Capacitance and Resistance Effects of Implantable Electrodes Using Fourier Transform AC Voltammetry on Platinum

Journal Article


Abstract


  • The charge transfer mechanism at the electrode-solution interface was assessed by Fourier transform AC voltammetry (FTACV).

    The faradaic reactions that occur within the safe potential window on platinum had slow electron transfer kinetics. The charge

    transfer mechanisms during short chronopotentiometric stimulation of cells, is most likely dominated by capacitance. Impedance

    was modelled with a single time constant. FTACV was fit with a 2-component equivalent circuit comprising a series capacitor and

    resistor. Capacitance and resistance varied with electrode potential, area, topography, surface functionality and solution composition.

    Capacitance correlated with charge storage capacity measured by voltammetry. Increased capacitance reduced the change in potential

    during chronopotentiometry. Increased resistance resulted in uncompensated resistance, and a larger change in potential during

    chronopotentiometry. Uncompensated resistance in tissue may lead to the measured potential of an electrode being considerably

    higher than its true potential, leading to a conservative estimate of the safe operating potential window. An impedance test is used

    to assess electrode performance in vivo. The impedance test is a function of capacitance, faradaic charge and resistance. Impedance

    test results allow electrode comparison, indicating changes in electrode-tissue interface, electrode failure and power usage, however

    use of Ohm’s law to calculate an impedance value is not valid.

Authors


  •   Harris, Alexander R. (external author)
  •   Newbold, Carrie (external author)
  •   Cowan, Robert (external author)
  •   Wallace, Gordon G.

Publication Date


  • 2019

Citation


  • Harris, A. R., Newbold, C., Cowan, R. & Wallace, G. G. (2019). Insights into the Electron Transfer Kinetics, Capacitance and Resistance Effects of Implantable Electrodes Using Fourier Transform AC Voltammetry on Platinum. Journal Of The Electrochemical Society, 166 (12), G131-G140.

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/3723

Start Page


  • G131

End Page


  • G140

Volume


  • 166

Issue


  • 12

Place Of Publication


  • United States

Abstract


  • The charge transfer mechanism at the electrode-solution interface was assessed by Fourier transform AC voltammetry (FTACV).

    The faradaic reactions that occur within the safe potential window on platinum had slow electron transfer kinetics. The charge

    transfer mechanisms during short chronopotentiometric stimulation of cells, is most likely dominated by capacitance. Impedance

    was modelled with a single time constant. FTACV was fit with a 2-component equivalent circuit comprising a series capacitor and

    resistor. Capacitance and resistance varied with electrode potential, area, topography, surface functionality and solution composition.

    Capacitance correlated with charge storage capacity measured by voltammetry. Increased capacitance reduced the change in potential

    during chronopotentiometry. Increased resistance resulted in uncompensated resistance, and a larger change in potential during

    chronopotentiometry. Uncompensated resistance in tissue may lead to the measured potential of an electrode being considerably

    higher than its true potential, leading to a conservative estimate of the safe operating potential window. An impedance test is used

    to assess electrode performance in vivo. The impedance test is a function of capacitance, faradaic charge and resistance. Impedance

    test results allow electrode comparison, indicating changes in electrode-tissue interface, electrode failure and power usage, however

    use of Ohm’s law to calculate an impedance value is not valid.

Authors


  •   Harris, Alexander R. (external author)
  •   Newbold, Carrie (external author)
  •   Cowan, Robert (external author)
  •   Wallace, Gordon G.

Publication Date


  • 2019

Citation


  • Harris, A. R., Newbold, C., Cowan, R. & Wallace, G. G. (2019). Insights into the Electron Transfer Kinetics, Capacitance and Resistance Effects of Implantable Electrodes Using Fourier Transform AC Voltammetry on Platinum. Journal Of The Electrochemical Society, 166 (12), G131-G140.

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/3723

Start Page


  • G131

End Page


  • G140

Volume


  • 166

Issue


  • 12

Place Of Publication


  • United States