title: Conducting polymer electrodes for auditory brainstem implants.
abstract: The auditory brainstem implant (ABI) restores hearing in patients with damaged auditory nerves. One of the main ideas to improve the efficacy of ABIs is to increase spatial specificity of stimulation, in order to minimize extra-auditory side-effects and to maximize the tonotopy of stimulation. This study reports on the development of a microfabricated conformable electrode array with small (100μm diameter) electrode sites. The latter are coated with a conducting polymer, PEDOT:PSS, to offer high charge injection properties and to safely stimulate the auditory system with small stimulation sites. We report on the design and fabrication of the polymer implant, and characterize the coatings in physiological conditions in vitro and under mechanical deformation. We characterize the coating electrochemically and during bending tests. We present a proof of principle experiment where the auditory system is efficiently activated by the flexible polymeric interface in a rat model. These results demonstrate the potential of using conducting polymer coatings on small electrode sites for electrochemically safe and efficient stimulation of the central auditory system.
authors.affiliation: Center for Neuroprosthetics, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
authors.forename: Amélie A
authors.initials: AA
authors.lastname: Guex
authors.affiliation: Center for Neuroprosthetics, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vachicouras
authors.affiliation: Eaton-Peabody Laboratories and Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, and Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts.
authors.forename: Ariel E
authors.initials: AE
authors.lastname: Hight
authors.affiliation: Eaton-Peabody Laboratories and Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, and Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts.
authors.forename: M Christian
authors.initials: MC
authors.lastname: Brown
authors.affiliation: Eaton-Peabody Laboratories and Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, and Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: Center for Neuroprosthetics, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
authors.forename: Stéphanie P
authors.initials: SP
authors.lastname: Lacour