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Impedance spectroscopy and nanoindentation of conducting poly(3,4-ethylenedioxythiophene) coatings on microfabricated neural prosthetic devices

Published online by Cambridge University Press:  01 May 2006

Junyan Yang  and
David C. Martin
Junyan Yang
Affiliation:
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136
David C. Martin*
Affiliation:
Departments of Materials Science and Engineering, and Biomedical Engineering, and Macromolecular Science and Engineering Center, University of Michigan, Ann Arbor, Michigan 48109-2136
*
b) Address all correspondence to this author. e-mail: milty@umich.edu
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Abstract

The electrical and mechanical properties of conducting polymer poly(3,4-ethylenedioxythiophene) coatings on microfabricated neural probes have been evaluated by electrochemical impedance spectroscopy and nanoindentation techniques. Our results reveal that for poly(3,4-ethylenedioxythiophene) coatings, the minimum impedance correlates well with the mechanical properties. The lowest impedance films are also those that are the softest. This is consistent with microstructural observations by atomic force microscopy and scanning electron microscopy showing an increase in the effective surface area (“fuzziness”) of the coatings. The presence of these conducting polymer coatings provides an intermediate step along the interface between the devices and brain tissue. This information provides clues for the design of strategies for improving the long-term performance of these electrodes in vivo.

Keywords

FilmNanostructurePolymer
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 5 , May 2006 , pp. 1124 - 1132
Copyright
Copyright © Materials Research Society 2006

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