title: pHEMA Encapsulated PEDOT-PSS-CNT Microsphere Microelectrodes for Recording Single Unit Activity in the Brain.
abstract: The long-term reliability of neural interfaces and stability of high-quality recordings are still unsolved issues in neuroscience research. High surface area PEDOT-PSS-CNT composites are able to greatly improve the performance of recording and stimulation for traditional intracortical metal microelectrodes by decreasing their impedance and increasing their charge transfer capability. This enhancement significantly reduces the size of the implantable device though preserving excellent electrical performances. On the other hand, the presence of nanomaterials often rises concerns regarding possible health hazards, especially when considering a clinical application of the devices. For this reason, we decided to explore the problem from a new perspective by designing and testing an innovative device based on nanostructured microspheres grown on a thin tether, integrating PEDOT-PSS-CNT nanocomposites with a soft synthetic permanent biocompatible hydrogel. The pHEMA hydrogel preserves the electrochemical performance and high quality recording ability of PEDOT-PSS-CNT coated devices, reduces the mechanical mismatch between soft brain tissue and stiff devices and also avoids direct contact between the neural tissue and the nanocomposite, by acting as a biocompatible protective barrier against potential nanomaterial detachment. Moreover, the spherical shape of the electrode together with the surface area increase provided by the nanocomposite deposited on it, maximize the electrical contact and may improve recording stability over time. These results have a good potential to contribute to fulfill the grand challenge of obtaining stable neural interfaces for long-term applications.
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia 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 Ferrara, Italy.
authors.forename: Emma
authors.initials: E
authors.lastname: Maggiolini
authors.affiliation: Department of Smart Materials, Istituto Italiano di Tecnologia Genova, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Ceseracciu
authors.affiliation: Section of Human Physiology, University of Ferrara Ferrara, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ciarpella
authors.affiliation: Section of Human Physiology, University of Ferrara 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 Ferrara, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: De Faveri
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di TecnologiaFerrara, Italy; Section of Human Physiology, University of FerraraFerrara, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Fadiga
authors.affiliation: Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia Ferrara, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Ricci
keywords: PEDOT; biocompatibility; carbon nanotubes; microelectrode; neural recordings; pHEMA