Poly(3,4-ethylenedioxythiophene) (PEDOT) Polymer Coatings Facilitate Smaller Neural Recording Electrodes

J Neural Eng. 2011 Feb;8(1):014001. doi: 10.1088/1741-2560/8/1/014001. Epub 2011 Jan 19.


We investigated using poly(3,4-ethylenedioxythiophene) (PEDOT) to lower the impedance of small, gold recording electrodes with initial impedances outside of the effective recording range. Smaller electrode sites enable more densely packed arrays, increasing the number of input and output channels to and from the brain. Moreover, smaller electrode sizes promote smaller probe designs; decreasing the dimensions of the implanted probe has been demonstrated to decrease the inherent immune response, a known contributor to the failure of long-term implants. As expected, chronically implanted control electrodes were unable to record well-isolated unit activity, primarily as a result of a dramatically increased noise floor. Conversely, electrodes coated with PEDOT consistently recorded high-quality neural activity, and exhibited a much lower noise floor than controls. These results demonstrate that PEDOT coatings enable electrode designs 15 µm in diameter.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / standards
  • Bridged Bicyclo Compounds, Heterocyclic / chemistry*
  • Electrodes, Implanted / standards
  • Male
  • Microelectrodes* / standards
  • Motor Cortex / physiology
  • Neurons / physiology*
  • Polymers / chemistry*
  • Rats
  • Rats, Sprague-Dawley


  • Biocompatible Materials
  • Bridged Bicyclo Compounds, Heterocyclic
  • Polymers
  • poly(3,4-ethylene dioxythiophene)