Activated iridium oxide film (AIROF) electrodes for neural tissue stimulation.
Activated iridium oxide film (AIROF) electrodes for neural tissue stimulation.
复制标题
用于神经组织刺激的活化氧化铱膜（AIROF）电极。
DOI：
10.1088/1741-2552/abb9bf
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发表时间：
2020-10-13
影响因子：
4
通讯作者：
中科院分区：
文献类型：
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氧化铱薄膜通常用作神经器件中的高电荷注入电极材料。然而，很少有研究进行了深入的评估材料性能与膜厚度，特别是在中性pH电解质溶液中的三维（而不是平面）金属表面上生长的膜。此外，很少有研究调查了使用活化氧化铱（AIROF）电极的恒流刺激的驱动电压要求，这将是未来在无线供电神经设备中使用的关键约束。在本研究中，铱微丝探针通过在室温磷酸盐缓冲盐水（pH 7.1-7.3）中重复电位脉冲来激活。随着AIROF厚度的增加，在三种不同的电解质条件下记录了具有不同几何表面积（GSA）的探针的电化学测量结果。AIROF电极需要在脉冲间隔期间保持阳极电位偏置，以输送神经刺激所需的电荷水平。在具有2000 μm2铱探针的PBS中，100-200个循环的电势脉冲足以实现2.5 mC cm-2（在双相脉冲中为50 nC/相）的电荷注入水平。将电极表面积增加到3000 μm2和4000 μm2显著增加了电荷注入能力，降低了输送固定量电荷所需的驱动电压，并降低了恒流脉冲期间电极的极化。本研究建立了用于选择适合于神经组织插入和刺激的三维铱电极的激活方案和所需GSA的方法，并提供了使用模型盐水溶液评估AIROF电化学性能的指南。
Iridium oxide films are commonly used as a high charge-injection electrode material in neural devices. Yet, few studies have performed in-depth assessments of material performance versus film thickness, especially for films grown on three-dimensional (instead of planar) metal surfaces in neutral pH electrolyte solutions. Further, few studies have investigated the driving voltage requirements for constant-current stimulation using activated iridium oxide (AIROF) electrodes, which will be a key constraint for future use in wirelessly powered neural devices. In this study, iridium microwire probes were activated by repeated potential pulsing in room temperature phosphate buffered saline (pH 7.1–7.3). Electrochemical measurements were recorded in three different electrolyte conditions for probes with different geometric surface areas (GSAs) as the AIROF thickness was increased. Maintaining an anodic potential bias during the inter-pulse interval was required for AIROF electrodes to deliver charge levels considered necessary for neural stimulation. Potential pulsing for 100–200 cycles was sufficient to achieve charge injection levels of 2.5 mC cm−2 (50 nC/phase in a biphasic pulse) in PBS with 2000 μm2 iridium probes. Increasing the electrode surface area to 3000 μm2 and 4000 μm2 significantly increased charge-injection capacity, reduced the driving voltage required to deliver a fixed amount of charge, and reduced polarization of the electrodes during constant-current pulsing. This study establishes methods for choosing an activation protocol and a desired GSA for three-dimensional iridium electrodes suitable for neural tissue insertion and stimulation, and provides guidelines for evaluating electrochemical performance of AIROF using model saline solutions.
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DOI：
10.1039/f19767201896
发表时间：
1976-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS I
影响因子：
--
作者：
BUCKLEY, DN;BURKE, LD;MULCAHY, JK
通讯作者：
MULCAHY, JK
影响因子：
3.4
作者：
Cone JJ;Ni AM;Ghose K;Maunsell JHR
通讯作者：
Maunsell JHR
影响因子：
3.9
作者：
GOTTESFELD, S;MCINTYRE, JDE
通讯作者：
MCINTYRE, JDE
影响因子：
4.6
作者：
Cogan, SF;Troyk, PR;Plante, TD
通讯作者：
Plante, TD
影响因子：
3
作者：
Cogan, SF;Guzelian, AA;McCreery, DB
通讯作者：
McCreery, DB