Cogan Stuart F, Ehrlich Julia, Plante Timothy D, Smirnov Anton, Shire Douglas B, Gingerich Marcus, Rizzo Joseph F
EIC Laboratories, Norwood, Massachusetts 02062.
Department of Veterans Affairs, Center for Innovative Visual Rehabilitation, Cornell University, Ithaca, New York 14853.
J Biomed Mater Res B Appl Biomater. 2009 May;89(2):353-361. doi: 10.1002/jbm.b.31223.
Sputtered iridium oxide films (SIROFs) deposited by DC reactive sputtering from an iridium metal target have been characterized in vitro for their potential as neural recording and stimulation electrodes. SIROFs were deposited over gold metallization on flexible multielectrode arrays fabricated on thin (15 microm) polyimide substrates. SIROF thickness and electrode areas of 200-1300 nm and 1960-125,600 microm(2), respectively, were investigated. The charge-injection capacities of the SIROFs were evaluated in an inorganic interstitial fluid model in response to charge-balanced, cathodal-first current pulses. Charge injection capacities were measured as a function of cathodal pulse width (0.2-1 ms) and potential bias in the interpulse period (0.0 to 0.7 V vs. Ag|AgCl). Depending on the pulse parameters and electrode area, charge-injection capacities ranged from 1-9 mC/cm(2), comparable with activated iridium oxide films (AIROFs) pulsed under similar conditions. Other parameters relevant to the use of SIROF on nerve electrodes, including the thickness dependence of impedance (0.05-10(5) Hz) and the current necessary to maintain a bias in the interpulse region were also determined.
通过直流反应溅射从铱金属靶材沉积的溅射氧化铱薄膜（SIROF）已在体外对其作为神经记录和刺激电极的潜力进行了表征。SIROF沉积在薄（15微米）聚酰亚胺基板上制造的柔性多电极阵列上的金金属化层上。研究了SIROF的厚度和电极面积，分别为200 - 1300纳米和1960 - 125,600微米²。在无机间质液模型中，针对电荷平衡的阴极优先电流脉冲，评估了SIROF的电荷注入能力。测量了电荷注入能力与阴极脉冲宽度（0.2 - 1毫秒）以及脉冲间隔期间的电位偏置（相对于Ag|AgCl为0.0至0.7伏）的函数关系。根据脉冲参数和电极面积，电荷注入能力范围为1 - 9毫库仑/平方厘米，与在类似条件下脉冲处理的活性氧化铱薄膜（AIROF）相当。还确定了与在神经电极上使用SIROF相关的其他参数，包括阻抗（0.05 - 10⁵赫兹）的厚度依赖性以及在脉冲间隔区域维持偏置所需的电流。
