PEDOT-coated electrodes

Fig. 9 Comparison of the impedance modulus of the Pt electrode and PEDOT-coated Pt electrodes. The PEDOT/PSS was coated potentiometrically at room temperature with variable polymerization charge densities from 20, 40, 80 to 160 mC/cm. All 4 PEDOT-coated electrodes have reductions in impedance modulus at the frequency range of 10 kHz or lower while significant reductions appear at 1 kHz or lower...

In neural stimulation, conducting polymers are usually electrochemically deposited on metal seed layers such as Pt and Au. For such noncovalently coated polymer layers, the adhesion to metal is critical for the stability of long-term applications. In a recent study, the chronic behavior of PEDOT-coated electrodes was examined [33]. Thirty electrodes from three electrode arrays were stimulated and evaluated for stability. It was found that the well-coated PEDOT electrodes were... 

Futhermore, nanofiber scaffold electrodes based on PEDOT for cell stimulation were recently reported by Bolin et al. [87]. Electronically conductive and electrochemically active three-dimensional scaffolds based on electrospun poly(ethylene terephthalate) (PET) nanofibers were prepared. Vapor-phase polymerization was employed to achieve a uniform and conformal coating of poly(3,4-ethylenedioxythiophene) doped with tosylate (PEDOT tosylate) on the nanofibers. The PEDOT coatings had a large impact on the... 

Recently, we reported work on the evaluation of PEDOT for neural stimulation applications [33]. PEDOT was electrochemically deposited on thin-film Pt electrodes of stimulation electrode arrays to evaluate its properties for chronic stimulation. The coated electrodes demonstrated much lower impedance than thin-film Pt due to the high surface area and high ion conductivity across the film. The PEDOT film also presents intrinsic redox activity, which contributes to the low impedance as well as a much higher charge storage capacity. The charge injection limit of PEDOT electrodes was found to be 2.3 mC/cm, comparable to IrOx, and much higher than... 

Fig. 15 (a) Cyclic Voltammograms (CV) of PEDOT-coated and uncoated Pt electrodes. The CV scan rate was 100 mV/s. (b) The charge capacity as a function of deposition time (Reproduced from [33], with permission from IEEE)... 

Fig. 16 Current and voltage waveforms of a PEDOT-coated Pt electrode under pulse stimulation (a). The electrode was stimulated in PBS under a charge-balanced, cathodic-first, biphasic pulse current at 1 mC/cm at 50 Hz (b). Voltage excursion was measured under pulse stimulation currents to evaluate the PEDOT electrode charge injection capacity...

Cogan SF, Peramunage D, Smirnov A et al (2(X)7) Polyethylenedioxythiophene (PEDOT) coatings for neural stimulation and recording electrodes. Mater Res Soc Meet, (Abstr. QQ2.7), Nov. 26-30, 2007, Boston... 

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