Flexible active electrode arrays with ASICs that fit inside the rat’s spinal canal

Giagka, V.; Demosthenous, A.; Donaldson, N.

doi:doi:10.1007/s10544-015-0011-5

Flexible active electrode arrays with ASICs that fit inside the rat’s spinal canal

Title

Flexible active electrode arrays with ASICs that fit inside the rat’s spinal canal

Author

Giagka, V.
Demosthenous, A.
Donaldson, N.

Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Microelectronics

Date

2015-10-14

Abstract

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 (1.7 mm2) and thin (100 ?m) 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 1 mA, 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.

Subject

active flexible electrode arrays
application specific integrated circuits
epidural stimulation
laser patterned microelectrodes
neurorehabilitation
rivet bonding

To reference this document use:

http://resolver.tudelft.nl/uuid:55aee12d-4295-4a4a-afe8-2007be5673aa

Publisher

Springer

ISSN

1387-2176

Source

https://doi.org/10.1007/s10544-015-0011-5

Source

Biomedical Microdevices, 17, 2015