Feasibility of microelectrode array (MEA) based on silicone-polyimide hybrid for retina prosthesis.
OBJECTIVE
To adopt micropatterning technology in manufacturing silicone elastomer-based microelectrode arrays for retinal stimulation, a silicone-polyimide hybrid microelectrode array was proposed and tested in vivo.


METHODS
Gold microelectrodes were created by semiconductor manufacturing technology based on polyimide and were hybridized with silicone elastomer by spin coating. The stability of the hybrid between the two materials was flex and blister tested. The feasibility of the hybrid electrode was evaluated in the rabbit eye by reviewing optical coherence tomography (OCT) findings after suprachoroidal implantation.


RESULTS
The flex test showed no dehiscence between the two materials for 24 hours of alternative flexion and extension from -45.0 degrees to +45.0 degrees . During the blister test, delamination was observed at 8.33 +/- 1.36 psi of pressure stress; however, this property was improved to 11.50 +/- 1.04 psi by oxygen plasma treatment before hybridization. OCT examination revealed that the implanted electrodes were safely located in the suprachoroidal space during the 4-week follow-up period.


CONCLUSIONS
The silicone-polyimide hybrid microelectrode array showed moderate physical properties, which are suitable for in vivo application. Appropriate pretreatment before hybridization improved electrode stability. In vivo testing indicated that this electrode is suitable as a stimulation electrode in artificial retina.
Kim
Eui Tae
ET
School of Electrical Engineering and Computer Science, Seoul National University College of Medicine, Seoul, Korea.
Kim
Cinoo
C
Lee
Seung Woo
SW
Seo
Jong-Mo
JM
Chung
Hum
H
Kim
Sung June
SJ
D000818:Animals; D001187:Artificial Organs; D001672:Biocompatible Materials; D004567:Electrodes, Implanted; D005240:Feasibility Studies; D006046:Gold; D008839:Microelectrodes; D009757:Nylons; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D011817:Rabbits; D012160:Retina / Q000601:surgery*; D012826:Silicone Elastomers; D041623:Tomography, Optical Coherence
D001672:Biocompatible Materials; D009757:Nylons; D012826:Silicone Elastomers; D006046:Gold