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BioMed Research International
Volume 2015, Article ID 109702, 10 pages
Research Article

Highly Flexible Silicone Coated Neural Array for Intracochlear Electrical Stimulation

1School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
2Department of Rehabilitative Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
3Department of Otolaryngology-Head & Neck Surgery, Georgia Regents University, Augusta, GA 30912, USA
4Department of Neurology, Brain and Behavior Discovery Institute, Georgia Regents University, Augusta, GA 30912, USA
5Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA
6The Shea Ear Clinic, Memphis, TN 38119, USA
7Department of Otolaryngology-Head and Neck Surgery, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA

Received 20 August 2014; Accepted 22 January 2015

Academic Editor: Chung-Feng Hwang

Copyright © 2015 P. Bhatti et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We present an effective method for tailoring the flexibility of a commercial thin-film polymer electrode array for intracochlear electrical stimulation. Using a pneumatically driven dispensing system, an average μm (mean ± SD) thickness layer of silicone adhesive coating was applied to stiffen the underside of polyimide multisite arrays. Additional silicone was applied to the tip to protect neural tissue during insertion and along the array to improve surgical handling. Each array supported 20 platinum sites (180 μm dia., 250 μm pitch), spanning nearly 28 mm in length and 400 μm in width. We report an average intracochlear stimulating current threshold of μA to evoke an auditory brainstem response in 7 acutely deafened felines. A total of 10 arrays were each inserted through a round window approach into the cochlea’s basal turn of eight felines with one delamination occurring upon insertion (preliminary results of the in vivo data presented at the 48th Annual Meeting American Neurotology Society, Orlando, FL, April 2013, and reported in Van Beek-King 2014). Using microcomputed tomography imaging (50 μm resolution), distances ranging from 100 to 565 μm from the cochlea’s central modiolus were measured. Our method combines the utility of readily available commercial devices with a straightforward postprocessing step on the order of 24 hours.