Transparent microelectrodes that facilitate simultaneous optical and electrophysiological interfacing are desirable tools for neuroscience. Electrodes made from transparent conductors such as graphene and indium tin oxide (ITO) show promise but are often limited by poor charge‐transfer properties. Herein, microelectrodes are demonstrated that take advantage of the transparency and volumetric capacitance of poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). Ring‐shaped microelectrodes are fabricated by inkjet‐printing PEDOT:PSS, encapsulating with Parylene C, and then exposing a contact site that is much smaller than the microelectrode outer diameter. This unique structure allows the encapsulated portion of the microelectrode volume surrounding the contact site to participate in signal transduction, which reduces impedance and enhances charge storage capacity. While using the same 100 μm diameter contact site, increasing the outer diameter of the encapsulated electrode from 300 to 550 μm reduces the impedance from 294 ± 21 to 98 ± 2 kΩ, respectively, at 1 Hz. Similarly, the charge storage capacity is enhanced from 6 to 21 mC cm−2. The PEDOT:PSS microelectrodes provide a low‐haze, high‐transmittance optical interface, demonstrating their suitability for optical neuroscience applications. They remain functional after a million 1 V stimulation cycles, up to 600 μA of stimulation current, and more than 1000 mechanical bending cycles.
- Award ID(s):
- 1808436
- PAR ID:
- 10282378
- Date Published:
- Journal Name:
- Lab on a Chip
- Volume:
- 21
- Issue:
- 6
- ISSN:
- 1473-0197
- Page Range / eLocation ID:
- 1096 to 1108
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d0lc01123a
