TY - JOUR

T1 - Aligned carbon nanotube-liquid silicone rubber conductors and electrode surfaces for stimulating medical implants

AU - Tegtmeier, Katharina

AU - Aliuos, Pooyan

AU - Stieghorst, Jan

AU - Schickedanz, Malte

AU - Golly, Felix

AU - Zernetsch, Holger

AU - Glasmacher, Birgit

AU - Doll, Theodor

N1 - This work has been partially sup-ported by Deutsche Forschungsgemeinschaft (DFG, SFB 599), theGerman Cluster of Excellence“Hearing4All and Lower AustriaLife Science grants LS 010–017.

PY - 2014/6/11

Y1 - 2014/6/11

N2 - Cochlear implants restore the inner ear hearing using electrical stimulation of the auditory nerve. However, there is potential to improve the implant's function in terms of stimulation selectivity by increasing the number of electrode contacts. Meanwhile, the electrode stiffness shall not be elevated, because this would enhance insertion trauma and fibrous tissue encapsulation of the implant. Since the increase in the number of electrode contacts results in an increase of electrode stiffness, novel materials are needed for manufacturing electrode shafts. Carbon nanotubes (CNTs) as electrode contacts offer new perspectives concerning mechanical properties and electrode-nerve interfacing. However, by using CNTs immersed in liquid silicone rubber (LSR) as electrode material, the electrical conductivity of the bulk needs to be improved. The aim of this study was to investigate the potential of using CNT-LSR as electrode material by increasing the conductivity of such materials and confirming their biocompatibility. First results show, that the electrode material can be printed in isolated layers, while the conductivity of the bulk can be improved. Fibroblasts growth tests indicated biocompatible properties of CNT-LSR samples. In conclusion CNT-LSR materials can be considered as promising candidates for use in neural implants possessing proper mechanical, electrical as well as biocompatible properties.

AB - Cochlear implants restore the inner ear hearing using electrical stimulation of the auditory nerve. However, there is potential to improve the implant's function in terms of stimulation selectivity by increasing the number of electrode contacts. Meanwhile, the electrode stiffness shall not be elevated, because this would enhance insertion trauma and fibrous tissue encapsulation of the implant. Since the increase in the number of electrode contacts results in an increase of electrode stiffness, novel materials are needed for manufacturing electrode shafts. Carbon nanotubes (CNTs) as electrode contacts offer new perspectives concerning mechanical properties and electrode-nerve interfacing. However, by using CNTs immersed in liquid silicone rubber (LSR) as electrode material, the electrical conductivity of the bulk needs to be improved. The aim of this study was to investigate the potential of using CNT-LSR as electrode material by increasing the conductivity of such materials and confirming their biocompatibility. First results show, that the electrode material can be printed in isolated layers, while the conductivity of the bulk can be improved. Fibroblasts growth tests indicated biocompatible properties of CNT-LSR samples. In conclusion CNT-LSR materials can be considered as promising candidates for use in neural implants possessing proper mechanical, electrical as well as biocompatible properties.

KW - carbon nanotubes

KW - cochlear implants

KW - electrodes

KW - neurostimulation

UR - http://www.scopus.com/inward/record.url?scp=84902547842&partnerID=8YFLogxK

U2 - 10.1002/pssa.201330405

DO - 10.1002/pssa.201330405

M3 - Article

AN - SCOPUS:84902547842

VL - 211

SP - 1439

EP - 1447

JO - Physica Status Solidi (A) Applications and Materials Science

JF - Physica Status Solidi (A) Applications and Materials Science

SN - 1862-6300

IS - 6

ER -