Carpio-Verdín Víctor Manuel, Hernández-Sebastián Natiely, Barrientos-García Bernardino, Solis-Ortiz Silvia, Bojorges-Valdez Erik R, López-Huerta Francisco, Mares-Castro Carlos Ismael, Calleja-Arriaga Wilfrido
Centro de Investigaciones en Óptica, A.C. Loma del Bosque 115, León 37150, Mexico.
Departamento de Ciencias Médicas, División de Ciencias de la Salud, Universidad de Guanajuato, 20 de enero 929, León 37320, Mexico.
Sensors (Basel). 2025 Aug 21;25(16):5198. doi: 10.3390/s25165198.
Transcorneal electrical stimulation (TES) is a promising treatment for several retinal degenerative diseases (RDDs). TES involves the application of a controlled electrical current to the anterior surface of the cornea, aimed at activating the retina and posterior ocular structures. Dawson-Trick-Litzkow (DTL) and ERG-JET electrodes are among the most widely used for TES. However, their continuous metallic surface design limits spatial resolution and the ability to perform selective ES. In this work, we present the development of a transcorneal electrical stimulation (TES) electrode that, unlike conventional electrodes, enables spatially selective TES. The proposed electrode design consists of an array of 20 independent microelectrodes distributed across the central and paracentral regions of the cornea. The fabrication process combines surface micromachining and flexible electronics technologies, employing only three structural materials: aluminum (Al), titanium (Ti), and polyimide (PI). This material selection is critical for achieving a simplified, reproducible, and low-cost fabrication process. The fabricated electrode was validated through electrical and electrochemical testing. The results show a relatively high electrical conductivity of Al/Ti structures, low electrochemical impedance values-ranging from 791 kΩ to 1.75 MΩ for the clinically relevant frequency range (11 to 30 Hz)-and a high charge storage capacity of 1437 mC/cm. The electrode capacity for electrical signal transmission was demonstrated through in vitro testing. Finally, the applicability of the TES electrode for electroretinogram (ERG) recording was evaluated by measuring its optical transmittance across the visible wavelength range.
经角膜电刺激（TES）是几种视网膜退行性疾病（RDD）的一种有前景的治疗方法。TES包括向角膜前表面施加可控电流，旨在激活视网膜和眼后结构。道森-特里克-利茨科夫（DTL）电极和ERG-JET电极是TES中使用最广泛的电极。然而，它们连续的金属表面设计限制了空间分辨率和进行选择性电刺激（ES）的能力。在这项工作中，我们展示了一种经角膜电刺激（TES）电极的开发，与传统电极不同，它能够进行空间选择性TES。所提出的电极设计由分布在角膜中央和旁中央区域的20个独立微电极阵列组成。制造工艺结合了表面微加工和柔性电子技术，仅使用三种结构材料：铝（Al）、钛（Ti）和聚酰亚胺（PI）。这种材料选择对于实现简化、可重复且低成本的制造工艺至关重要。通过电气和电化学测试对制造的电极进行了验证。结果显示Al/Ti结构具有相对较高的电导率，在临床相关频率范围（11至30 Hz）内电化学阻抗值较低，为791 kΩ至1.75 MΩ，并且电荷存储容量高达1437 mC/cm。通过体外测试证明了该电极传输电信号的能力。最后，通过测量其在可见波长范围内的光学透过率，评估了TES电极用于视网膜电图（ERG）记录的适用性。
