title: Design, fabrication and characterization of a low-impedance 3D electrode array system for neuro-electrophysiology.
abstract: Recent progress in patterned microelectrode manufacturing technology and microfluidics has opened the way to a large variety of cellular and molecular biosensor-based applications. In this extremely diverse and rapidly expanding landscape, silicon-based technologies occupy a special position, given their statute of mature, consolidated, and highly accessible areas of development. Within the present work we report microfabrication procedures and workflows for 3D patterned gold-plated microelectrode arrays (MEA) of different shapes (pyramidal, conical and high aspect ratio), and we provide a detailed characterization of their physical features during all the fabrication steps to have in the end a reliable technology. Moreover, the electrical performances of MEA silicon chips mounted on standardized connector boards via ultrasound wire-bonding have been tested using non-destructive electrochemical methods: linear sweep and cyclic voltammetry, impedance spectroscopy. Further, an experimental recording chamber package suitable for  in vitro electrophysiology experiments has been realized using custom-design electronics for electrical stimulus delivery and local field potential recording, included in a complete electrophysiology setup, and the experimental structures have been tested on newborn rat hippocampal slices, yielding similar performance compared to commercially available MEA equipments.
authors.affiliation: Laboratory of Nanobiotechnology, National Institute for Research and Development in Microtechnologies (IMT-Bucharest), 126A, Erou Iancu Nicolae Street, 077190 Bucharest, Romania. mihaela.kusko@imt.ro
authors.forename: Mihaela
authors.initials: M
authors.lastname: Kusko
authors.forename: Florea
authors.initials: F
authors.lastname: Craciunoiu
authors.forename: Bogdan
authors.initials: B
authors.lastname: Amuzescu
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Halitzchi
authors.forename: Tudor
authors.initials: T
authors.lastname: Selescu
authors.forename: Antonio
authors.initials: A
authors.lastname: Radoi
authors.forename: Marian
authors.initials: M
authors.lastname: Popescu
authors.forename: Monica
authors.initials: M
authors.lastname: Simion
authors.forename: Adina
authors.initials: A
authors.lastname: Bragaru
authors.forename: Teodora
authors.initials: T
authors.lastname: Ignat
mesh_terms: D000818:Animals; D017097:Electric Impedance; D004594:Electrophysiology / Q000295:instrumentation*; D006801:Humans; D009417:Nerve Tissue / Q000503:physiopathology*; D051381:Rats