caa a22 4500 605479518 CHVBK 20210128100410.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s10544-015-0011-5 doi (NATIONALLICENCE)springer-10.1007/s10544-015-0011-5 Flexible active electrode arrays with ASICs that fit inside the rat's spinal canal [Elektronische Daten] [Vasiliki Giagka, Andreas Demosthenous, Nick Donaldson] Epidural spinal cord electrical stimulation (ESCS) has been used as a means to facilitate locomotor recovery in spinal cord injured humans. Electrode arrays, instead of conventional pairs of electrodes, are necessary to investigate the effect of ESCS at different sites. These usually require a large number of implanted wires, which could lead to infections. This paper presents the design, fabrication and evaluation of a novel flexible active array for ESCS in rats. Three small (1.7mm2) and thin (100μm) application specific integrated circuits (ASICs) are embedded in the polydimethylsiloxane-based implant. This arrangement limits the number of communication tracks to three, while ensuring maximum testing versatility by providing independent access to all 12 electrodes in any configuration. Laser-patterned platinum-iridium foil forms the implant's conductive tracks and electrodes. Double rivet bonds were employed for the dice microassembly. The active electrode array can deliver current pulses (up to 1mA, 100 pulses per second) and supports interleaved stimulation with independent control of the stimulus parameters for each pulse. The stimulation timing and pulse duration are very versatile. The array was electrically characterized through impedance spectroscopy and voltage transient recordings. A prototype was tested for long term mechanical reliability when subjected to continuous bending. The results revealed no track or bond failure. To the best of the authors' knowledge, this is the first time that flexible active electrode arrays with embedded electronics suitable for implantation inside the rat's spinal canal have been proposed, developed and tested in vitro. The Author(s), 2015 Active flexible electrode arrays nationallicence Application specific integrated circuits nationallicence Epidural stimulation nationallicence Laser patterned microelectrodes nationallicence Neurorehabilitation nationallicence Rivet bonding nationallicence Giagka Vasiliki Department of Medical Physics and Biomedical Engineering, University College London, WC1E 6BT, London, UK aut Demosthenous Andreas Department of Electronic and Electrical Engineering, University College London, WC1E 7JE, London, UK aut Donaldson Nick Department of Medical Physics and Biomedical Engineering, University College London, WC1E 6BT, London, UK aut Biomedical Microdevices Springer US; http://www.springer-ny.com 17/6(2015-12-01), 1-13 1387-2176 17:6<1 2015 17 10544 https://doi.org/10.1007/s10544-015-0011-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10544-015-0011-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Giagka Vasiliki Department of Medical Physics and Biomedical Engineering, University College London, WC1E 6BT, London, UK aut NATIONALLICENCE 700 1- Demosthenous Andreas Department of Electronic and Electrical Engineering, University College London, WC1E 7JE, London, UK aut NATIONALLICENCE 700 1- Donaldson Nick Department of Medical Physics and Biomedical Engineering, University College London, WC1E 6BT, London, UK aut NATIONALLICENCE 773 0- Biomedical Microdevices Springer US; http://www.springer-ny.com 17/6(2015-12-01), 1-13 1387-2176 17:6<1 2015 17 10544