title: Chip-scale hermetic feedthroughs for implantable bionics.
abstract: Most implantable medical devices such as cochlear implants and visual prostheses require protection of the stimulating electronics. This is achieved by way of a hermetic feedthrough system which typically features three important attributes: biocompatibility with the human body, device hermeticity and density of feedthrough conductors. On the quest for building a visual neuroprosthesis, a high number of stimulating channels is required. This has encouraged new technologies with higher rates of production yield and further miniaturization. An Al(2)O(3) based feedthrough system has been developed comprising up to 20 platinum feedthroughs per square millimeter. Ceramics substrates are shown to have leak rates below 1 × 10(-12) atm × cc/s, thus exceeding the resolution limits of most commercially available leak detectors. A sheet resistance of 0.05 Ω can be achieved. This paper describes the design, fabrication process and hermeticity testing of high density feedthroughs for use in neuroprosthetic implants.
authors.affiliation: Faculty of Engineering, Graduate School of Biomedical Engineering, The University of New South Wales, Kensington, NSW 2052, Australia. Thomas.guenther@unsw.edu.au
authors.forename: Thomas
authors.initials: T
authors.lastname: Guenther
authors.forename: Christopher W D
authors.initials: CW
authors.lastname: Dodds
authors.forename: Nigel H
authors.initials: NH
authors.lastname: Lovell
authors.forename: Gregg J
authors.initials: GJ
authors.lastname: Suaning
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D001698:Biomedical Engineering / Q000379:methods*; D001701:Bionics; D002516:Ceramics; D004553:Electric Conductivity; D017097:Electric Impedance; D004567:Electrodes, Implanted; D004581:Electronics / Q000295:instrumentation; D004867:Equipment Design; D005740:Gases; D006801:Humans; D008904:Miniaturization / Q000295:instrumentation; D010984:Platinum / Q000737:chemistry; D019736:Prostheses and Implants; D013499:Surface Properties; D013686:Telemetry / Q000295:instrumentation
chemical_list: D001672:Biocompatible Materials; D005740:Gases; D010984:Platinum; D000537:Aluminum Oxide