Correlation of Impedance and Effective Electrode Area of Dextran Sulfate Doped PEDOT Modified Electrodes
Alexander R Harris, Robyn Hutchinson, Paul J Molino, Robert MI Kapsa, Graeme M Clark, Antonio G Paolini, Gordon G Wallace
JOURNAL OF THE ELECTROCHEMICAL SOCIETY | ELECTROCHEMICAL SOC INC | Published : 2016
The impedance of electrodes at 1 kHz is typically reported to assess the signal-to-noise ratio of neural recording electrodes. The impedance response of platinum electrodes modified by poly-3,4-ethylenedioxythiophene doped with dextran sulfate has been examined. The modified electrodes have lower impedance at low and intermediate frequencies compared to unmodified electrodes. The impedance and phase angle at low frequencies is strongly correlated with the electrode area. The geometric and linear diffusion charge densities of the modified electrodes are also dependent on the electrode area and impedance at low frequencies. A 3 time constant equivalent circuit provided a better fit to the impe..View full abstract
Awarded by Australian Research Council Centre of Excellence
Awarded by ARC under Australian Laureate Fellowship
Funding from the Australian Research Council Centre of Excellence Scheme (Project Numbers CE0561616 and CE140100012) are gratefully acknowledged. GGW is also grateful to the ARC for support under the Australian Laureate Fellowship scheme (FL110100196). The authors acknowledge the support of the Australian National Fabrication Facility (ANFF). The authors acknowledge use of the facilities and the assistance of Tony Romeo at the UOW Electron Microscopy Centre.