title: Highly Stable Glassy Carbon Interfaces for Long-Term Neural Stimulation and Low-Noise Recording of Brain Activity.
abstract: We report on the superior electrochemical properties, in-vivo performance and long term stability under electrical stimulation of a new electrode material fabricated from lithographically patterned glassy carbon. For a direct comparison with conventional metal electrodes, similar ultra-flexible, micro-electrocorticography (μ-ECoG) arrays with platinum (Pt) or glassy carbon (GC) electrodes were manufactured. The GC microelectrodes have more than 70% wider electrochemical window and 70% higher CTC (charge transfer capacity) than Pt microelectrodes of similar geometry. Moreover, we demonstrate that the GC microelectrodes can withstand at least 5 million pulses at 0.45 mC/cm2charge density with less than 7.5% impedance change, while the Pt microelectrodes delaminated after 1 million pulses. Additionally, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) was selectively electrodeposited on both sets of devices to specifically reduce their impedances for smaller diameters (<60 μm). We observed that PEDOT-PSS adhered significantly better to GC than Pt, and allowed drastic reduction of electrode size while maintaining same amount of delivered current. The electrode arrays biocompatibility was demonstrated through in-vitro cell viability experiments, while acute in vivo characterization was performed in rats and showed that GC microelectrode arrays recorded somatosensory evoked potentials (SEP) with an almost twice SNR (signal-to-noise ratio) when compared to the Pt ones.
authors.affiliation: MEMS Research Lab., Department of Mechanical Engineering, College of Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1323, USA.|Center for Sensorimotor Neural Engineering (CSNE), Box 37, 1414 NE 42nd St., Suite 204, Seattle, WA 98105-6271, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Vomero
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Castagnola
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.|Section of Human Physiology, University of Ferrara, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ciarpella
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.
authors.forename: Emma
authors.initials: E
authors.lastname: Maggiolini
authors.affiliation: MEMS Research Lab., Department of Mechanical Engineering, College of Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1323, USA.|Center for Sensorimotor Neural Engineering (CSNE), Box 37, 1414 NE 42nd St., Suite 204, Seattle, WA 98105-6271, USA.
authors.forename: Noah
authors.initials: N
authors.lastname: Goshi
authors.affiliation: Section of Human Physiology, University of Ferrara, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Zucchini
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Carli
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.|Section of Human Physiology, University of Ferrara, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Fadiga
authors.affiliation: MEMS Research Lab., Department of Mechanical Engineering, College of Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1323, USA.|Center for Sensorimotor Neural Engineering (CSNE), Box 37, 1414 NE 42nd St., Suite 204, Seattle, WA 98105-6271, USA.
authors.forename: Sam
authors.initials: S
authors.lastname: Kassegne
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121, Ferrara, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Ricci
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D002244:Carbon / Q000737:chemistry; D002470:Cell Survival; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D008839:Microelectrodes; D009424:Nervous System Physiological Phenomena; D009474:Neurons / Q000502:physiology; D011137:Polystyrenes / Q000737:chemistry; D051381:Rats; D059629:Signal-To-Noise Ratio; D013876:Thiophenes / Q000737:chemistry
chemical_list: D011137:Polystyrenes; D013876:Thiophenes; C533756:poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); D002244:Carbon