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

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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.

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References

  1. C.J. Buchko, M.J. Slattery, K.M. Kozloff, D.C. Martin: Mechanical properties of biocompatible protein polymer thin films. J. Mater. Res. 15(1), 231 (2000).

    Article  CAS  Google Scholar 

  2. A. Kros, S.W.F.M. van Hövell, N.A.J.M. Sommerdijk, R.J.M. Nolte: Poly(3,4-ethylenedioxythiophene)-based glucose biosensors. Adv. Mater. 13, 1555 (2001).

    Article  CAS  Google Scholar 

  3. E. Smela: Conjugated polymer actuators for biomedical applications. Adv. Mater. 15(6), 481 (2003).

    Article  CAS  Google Scholar 

  4. H. Yamato, M. Ohwa, W. Wernet: Stability of polypyrrole and poly(3,4-ethylenedioxythiophene) for biosensor application. J. Electroanal. Chem. 397, 163 (1995).

    Article  Google Scholar 

  5. X.Y. Cui, D.C. Martin: Electrochemical deposition and characterization of poly(3,4-ethylenedioxythiophene) on neural microelectrode arrays. Sens. Actuators B Chem. 89, 92 (2003).

    Article  CAS  Google Scholar 

  6. J. Yang, D.C. Martin: Microporous conducting polymers on neural prosthetic devices. I. Electrochemical deposition. Sens. Actuators B Chem. 101, 133 (2004).

    Article  CAS  Google Scholar 

  7. J. Yang, D.C. Martin: Microporous conducting polymers on neural prosthetic devices. II. Physical characterization. Sens. Actuators A Phys. 113, 72 (2004).

    Google Scholar 

  8. J. Yang, D.H. Kim, J.L. Hendricks, M. Leach, R. Northey, D.C. Martin: Ordered surfactant-templated poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer on microfabricated neural probes. Acta Biomaterialia 1, 125 (2005).

    Article  Google Scholar 

  9. X.S. Wang, X.Q. Feng: Effects of thickness on mechanical properties of conducting polythiophene films. J. Mater. Sci. Lett. 21, 715 (2002).

    Article  CAS  Google Scholar 

  10. X.S. Wang, J.K. Xu, G.Q. Shi, X. Lu: Microstructure-mechanical properties relationships in conducting polypyrrole films. J. Mater. Sci. 37, 5171 (2002).

    Article  CAS  Google Scholar 

  11. H. Yamato, K.I. Kai, M. Ohwa, W. Wernet, M. Matsumura: Mechanical, electrochemical and optical properties of poly(3,4-ethylenedioxythiophene)/sulfated poly(ß-hydrooxyethers) composites films. Electrochim. Acta 42, 2517 (1997).

    Article  CAS  Google Scholar 

  12. B.J. Briscoe, L. Fiori, E. Pelillo: Nanoindentation of polymeric surface. J. Phys. D: Appl. Phys. 31, 2395 (1998).

    Article  CAS  Google Scholar 

  13. T.H. Fang, W.J. Chang: Nanoindentation characteristics on polycarbonate polymer film. Microelectron. J. 35, 595 (2004).

    Article  CAS  Google Scholar 

  14. B.D. Beake, G.J. Leggett: Nanoindentation and nanoscratch testing of uniaxially and biaxially drawn poly(ethylene, terephthalate). Polymer 43, 319 (2002).

    Article  CAS  Google Scholar 

  15. P.V. Pavoor, A. Bellare, A. Strom, D. Yang, R.E. Cohen: Mechanical characterization of polyelectrolyte multilayers using quasi-static nanoindentation. Macromolecules 37, 4865 (2004).

    Article  CAS  Google Scholar 

  16. W.C. Oliver, G.M. Pharr: An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7, 1564 (1992).

    Article  CAS  Google Scholar 

  17. S.W. Kuffler: From Neuron to Brain: A Cellular Approach to the Function of the Nervous System. (Sinauer Associates, Sunerland, MA, 1976).

    Google Scholar 

  18. X. Cui, J.F. Jetke, J.A. Wiler, D.J. Anderson, D.C. Martin: Electrochemical deposition and characterization of conducting polymer polypyrrole/PSS on multichannel neural Probes. Sens. Actuators A Phys. 93, 8 (2001).

    Article  CAS  Google Scholar 

  19. C.J. Buchko, K.M. Kozloff, D.C. Martin: Surface characterization of porous, biocompatible protein polymer thin films. Biomaterials 22, 1289 (2001).

    Article  CAS  Google Scholar 

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Correspondence to Junyan Yang.

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Yang, J., Martin, D.C. Impedance spectroscopy and nanoindentation of conducting poly(3,4-ethylenedioxythiophene) coatings on microfabricated neural prosthetic devices. Journal of Materials Research 21, 1124–1132 (2006). https://doi.org/10.1557/jmr.2006.0145

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  • DOI: https://doi.org/10.1557/jmr.2006.0145

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