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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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References

REFERENCES

1.Buchko, C.J., Slattery, M.J., Kozloff, K.M., Martin, D.C.: Mechanical properties of biocompatible protein polymer thin films. J. Mater. Res. 15(1), 231 (2000).CrossRefGoogle Scholar
2.Kros, A., van Hövell, S.W.F.M., Sommerdijk, N.A.J.M., Nolte, R.J.M.: Poly(3,4-ethylenedioxythiophene)-based glucose biosensors. Adv. Mater. 13, 1555 (2001).3.0.CO;2-7>CrossRefGoogle Scholar
3.Smela, E.: Conjugated polymer actuators for biomedical applications. Adv. Mater. 15(6), 481 (2003).CrossRefGoogle Scholar
4.Yamato, H., Ohwa, M., Wernet, W.: Stability of polypyrrole and poly(3,4-ethylenedioxythiophene) for biosensor application. J. Electroanal. Chem. 397, 163 (1995).Google Scholar
5.Cui, X.Y., Martin, D.C.: Electrochemical deposition and characterization of poly(3,4-ethylenedioxythiophene) on neural microelectrode arrays. Sens. Actuators B Chem. 89, 92 (2003).CrossRefGoogle Scholar
6.Yang, J., Martin, D.C.: Microporous conducting polymers on neural prosthetic devices. I. Electrochemical deposition. Sens. Actuators B Chem. 101, 133 (2004).Google Scholar
7.Yang, J., Martin, D.C.: Microporous conducting polymers on neural prosthetic devices. II. Physical characterization. Sens. Actuators A Phys. 113, 72 (2004).Google Scholar
8.Yang, J., Kim, D.H., Hendricks, J.L., Leach, M., Northey, R., Martin, D.C.: Ordered surfactant-templated poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer on microfabricated neural probes. Acta Biomaterialia 1, 125 (2005).CrossRefGoogle Scholar
9.Wang, X.S., Feng, X.Q.: Effects of thickness on mechanical properties of conducting polythiophene films. J. Mater. Sci. Lett. 21, 715 (2002).Google Scholar
10.Wang, X.S., Xu, J.K., Shi, G.Q., Lu, X.: Microstructure-mechanical properties relationships in conducting polypyrrole films. J. Mater. Sci. 37, 5171 (2002).CrossRefGoogle Scholar
11.Yamato, H., Kai, K-I., Ohwa, M., Wernet, W., Matsumura, M.: Mechanical, electrochemical and optical properties of poly(3,4-ethylenedioxythiophene)/sulfated poly(β-hydrooxyethers) composites films. Electrochim. Acta 42, 2517 (1997).Google Scholar
12.Briscoe, B.J., Fiori, L., Pelillo, E.: Nanoindentation of polymeric surface. J. Phys. D: Appl. Phys. 31, 2395 (1998).CrossRefGoogle Scholar
13.Fang, T.H., Chang, W.J.: Nanoindentation characteristics on polycarbonate polymer film. Microelectron. J. 35, 595 (2004).CrossRefGoogle Scholar
14.Beake, B.D., Leggett, G.J.: Nanoindentation and nanoscratch testing of uniaxially and biaxially drawn poly(ethylene, terephthalate). Polymer 43, 319 (2002).CrossRefGoogle Scholar
15.Pavoor, P.V., Bellare, A., Strom, A., Yang, D., Cohen, R.E.: Mechanical characterization of polyelectrolyte multilayers using quasi-static nanoindentation. Macromolecules 37, 4865 (2004).Google Scholar
16.Oliver, W.C., Pharr, G.M.: An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7, 1564 (1992).Google Scholar
17.Kuffler, S.W.: From Neuron to Brain: A Cellular Approach to the Function of the Nervous System. (Sinauer Associates, Sunerland, MA, 1976).Google Scholar
18.Cui, X., Jetke, J.F., Wiler, J.A., Anderson, D.J., Martin, D.C.: Electrochemical deposition and characterization of conducting polymer polypyrrole/PSS on multichannel neural Probes. Sens. Actuators A Phys. 93, 8 (2001).CrossRefGoogle Scholar
19.Buchko, C.J., Kozloff, K.M., Martin, D.C.: Surface characterization of porous, biocompatible protein polymer thin films. Biomaterials 22, 1289 (2001).CrossRefGoogle ScholarPubMed