The development of a multichannel electrode array for retinal prostheses.
The development of a multielectrode array is the key issue for retinal prostheses. We developed a 10 x 10 platinum electrode array that consists of an 8-microm polyimide layer sandwiched between 5-microm polymonochloro-para-xylylene (parylene-C) layers. Each electrode was formed as a 30-microm-high bump by Pt/Au double-layer electroplating. We estimated the charge delivery capability (CDC) of the electrode by measuring the CDCs of two-channel electrode arrays. The dimensions of each electrode of the two-channel array were the same as those of each electrode formed on the 10 x 10 array. The results suggest that for cathodic-first (CF) pulses, 80% of electrodes surpassed our development target of 318 microC/cm2, which corresponds to the charge density of pulses of 500 micros duration and 200 microA amplitude for a 200-microm-diameter planar electrode.
Terasawa
Yasuo
Y
Vision Institute, Nidek Co, Ltd, Gamagori 443-0036, Japan. yasuo_terasawa@nidek.co.jp
Tashiro
Hiroyuki
H
Uehara
Akihiro
A
Saitoh
Tohru
T
Ozawa
Motoki
M
Tokuda
Takashi
T
Ohta
Jun
J
D004567:Electrodes, Implanted; D004595:Electroplating; D005074:Evoked Potentials, Visual; D005137:Eye, Artificial; D006801:Humans; D012160:Retina / Q000601:surgery*; D012590:Sclera / Q000601:surgery*