Institute of Microelectronics, Agency for Science, Technology and Research, Singapore 138634, Singapore.
Sensors (Basel). 2023 May 2;23(9):4453. doi: 10.3390/s23094453.
Dry electroencephalogram (EEG) systems have a short set-up time and require limited skin preparation. However, they tend to require strong electrode-to-skin contact. In this study, dry EEG electrodes with low contact impedance (<150 kΩ) were fabricated by partially embedding a polyimide flexible printed circuit board (FPCB) in polydimethylsiloxane and then casting them in a sensor mold with six symmetrical legs or bumps. Silver-silver chloride paste was used at the exposed tip of each leg or bump that must touch the skin. The use of an FPCB enabled the fabricated electrodes to maintain steady impedance. Two types of dry electrodes were fabricated: flat-disk electrodes for skin with limited hair and multilegged electrodes for common use and for areas with thick hair. Impedance testing was conducted with and without a custom head cap according to the standard 10-20 electrode arrangement. The experimental results indicated that the fabricated electrodes exhibited impedance values between 65 and 120 kΩ. The brain wave patterns acquired with these electrodes were comparable to those acquired using conventional wet electrodes. The fabricated EEG electrodes passed the primary skin irritation tests based on the ISO 10993-10:2010 protocol and the cytotoxicity tests based on the ISO 10993-5:2009 protocol.
干电极脑电图（EEG）系统具有较短的设置时间，且皮肤准备工作有限。然而，它们通常需要较强的电极与皮肤接触。在这项研究中，通过将聚酰亚胺柔性印刷电路板（FPCB）部分嵌入到聚二甲基硅氧烷中，然后将其浇注到具有六个对称支腿或凸块的传感器模具中，制造出具有低接触阻抗（<150 kΩ）的干电极。在每个支腿或凸块的暴露尖端使用银/氯化银糊剂，这些支腿或凸块必须接触皮肤。使用 FPCB 使得制造的电极能够保持稳定的阻抗。制造了两种类型的干电极：用于头发有限的皮肤的扁平盘电极和用于常见用途以及毛发较厚的区域的多足电极。根据标准的 10-20 电极排列，在带有和不带有定制头帽的情况下进行了阻抗测试。实验结果表明，所制造的电极具有 65 到 120 kΩ 的阻抗值。使用这些电极获得的脑波模式与使用传统湿电极获得的模式相当。根据 ISO 10993-10：2010 协议，所制造的 EEG 电极通过了初步皮肤刺激测试，并且根据 ISO 10993-5：2009 协议，通过了细胞毒性测试。
