Title: PEDOT:PSS coated gold nanopillar microelectrodes with ultralow impedance for neural interfaces

Authors: Christoph Nick; Helmut F. Schlaak; Christiane Thielemann

Addresses: BioMEMS Lab, University of Applied Sciences Aschaffenburg, Wuerzburger Str. 45, 63743 Aschaffenburg, Germany ' Microtechnology and Electromechanical Systems Laboratory, Institute of Electromechanical Design, Technische Universitaet Darmstadt, Merckstraße 25, 64283 Darmstadt, Germany ' BioMEMS Lab, University of Applied Sciences Aschaffenburg, Wuerzburger Str. 45, 63743 Aschaffenburg, Germany

Abstract: Improving the neuron-electrode interface has been a focus of biomedical research for the last decade. Low impedance, high charge storage capacities and small geometrical surface area are desired for excellent recording conditions. A common way to improve this interface is to increase the electrochemically active surface area of the electrode using nanoporous or nanostructured electrode materials. In this paper, the fabrication of microelectrodes with very high aspect ratio gold nanopillars coated with the conducting polymer PEDOT:PSS is presented. The electrodes are simulated, manufactured and studied using scanning electron microscopy, atomic force microscopy, impedance spectroscopy, cyclic voltammetry and neural cell culture experiments. We show that PEDOT:PSS coated nanopillar electrodes have improved capacity, reduced impedance and in-vitro recordings reveal high signal-to-noise ratio. Depending on pillar height the impedance is more than 350 times smaller compared to planar gold electrodes at 1 kHz and reveals an electrode capacity more than 1,000 times higher.

Keywords: gold nanopillars; microelectrodes; MEA; PEDOT:PSS; neural interface; neural cell culture; simulation; point-contact-model.

DOI: 10.1504/IJNM.2017.083849

International Journal of Nanomanufacturing, 2017 Vol.13 No.2, pp.109 - 128

Received: 05 Nov 2015
Accepted: 27 Nov 2015
Published online: 25 Apr 2017 *

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