A fully transparent, flexible PEDOT:PSS–ITO–Ag–ITO based microelectrode array for ECoG recording
- 22 January 2021
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Lab on a Chip
- Vol. 21 (6), 1096-1108
- https://doi.org/10.1039/d0lc01123a
Abstract
Integrative neural interfaces combining neurophysiology and optogenetics with neural imaging provide numerous opportunities for neuroscientists to study the structure and function of neural circuits in the brain. Such a comprehensive interface demands miniature electrode arrays with high transparency, mechanical flexibility, electrical conductivity, and biocompatibility. Conventional transparent microelectrodes made of a single material, such as indium tin oxide (ITO), ultrathin metals, graphene and poly-(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), hardly possess the desired combination of those properties. Herein, ultra-flexible, highly conductive and fully transparent microscale electrocorticogram (μECoG) electrode arrays made of a PEDOT:PSS–ITO–Ag–ITO assembly are constructed on thin parylene C films. The PEDOT:PSS–ITO–Ag–ITO assembly achieves a maximum ∼14% enhancement in light transmission over a broad spectrum (350–650 nm), a significant reduction in electrochemical impedance by 91.25%, and an increase in charge storage capacitance by 1229.78 μC cm−2. Peeling, bending, and Young's modulus tests verify the enhanced mechanical flexibility and robustness of the multilayer assembly. The μECoG electrodes enable electrical recordings with high signal-to-noise ratios (SNRs) (∼35–36 dB) under different color photostimulations, suggesting that the electrodes are resilient to photon-induced artifacts. In vivo animal experiments confirm that our array can successfully record light-evoked ECoG oscillations from the primary visual cortex (V1) of an anesthetized rat.Keywords
Funding Information
- Division of Electrical, Communications and Cyber Systems (1923187)
- Division of Civil, Mechanical and Manufacturing Innovation (1724941)
- Michigan State University
This publication has 48 references indexed in Scilit:
- Electrical and optical properties of indium-tin oxide (ITO) films by ion-assisted deposition (IAD) at room temperatureInternational Journal of Precision Engineering and Manufacturing, 2013
- Influence of Subsurface Hybrid Material Growth on the Mechanical Properties of Atomic Layer Deposited Thin Films on PolymersChemical Vapor Deposition, 2013
- Optogenetics as a neuromodulation tool in cognitive neuroscienceFrontiers in Psychology, 2013
- Room temperature crystallization of indium tin oxide films on glass and polyethylene terephthalate substrates using rf plasmaJournal of Vacuum Science & Technology A, 2007
- Admittance loci design method for multilayer surface plasmon resonance devicesSensors and Actuators B: Chemical, 2006
- Nanoindentation studies of materialsMaterials Today, 2006
- Room temperature indium tin oxide by XeCl excimer laser annealing for flexible displayThin Solid Films, 2004
- Elastic properties of indium tin oxide filmsThin Solid Films, 2001
- Stability of the interface between indium-tin-oxide and poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) in polymer light-emitting diodesApplied Physics Letters, 2000
- Low resistivity indium–tin oxide transparent conductive films. II. Effect of sputtering voltage on electrical property of filmsJournal of Vacuum Science & Technology A, 1990