Peng Hu, Kopic Inola, Potfode Shivani Ratnakar, Teshima Tetsuhiko F, Boustani George Al, Hiendlmeier Lukas, Wang Chen, Hussain Mian Zahid, Özkale Berna, Fischer Roland A, Wolfrum Bernhard
Neuroelectronics, Munich Institute of Biomedical Engineering, Department of Electrical Engineering, TUM School of Computation, Information and Technology, Technical University of Munich, Hans-Piloty-Str. 1, 85748, Garching, Germany.
Medical & Health Informatics Laboratories NTT Research Incorporated, 940 Stewart Dr, Sunnyvale, CA 94085, USA.
Nanoscale. 2024 Aug 7;16(30):14295-14301. doi: 10.1039/d4nr01727g.
Microelectrode arrays are commonly used to study the electrophysiological behavior of cells. Recently, there has been a growing interest in fabricating three-dimensional microelectrode arrays. Here, we present a novel process for the fast fabrication of epoxy-based 3D microelectrode array platforms with the assistance of laser-patterning technology. To this end, we photopatterned 3D pillars as scaffolds using epoxy-based dry films. Electrodes and conductor traces were fabricated by laser patterning of sputtered platinum films on top of the 3D structures, followed by deposition of parylene-C for insulation. Microelectrodes at the tip of the 3D structures were exposed using a vertical laser ablation process. The final electrodes demonstrated a low impedance of ∼10 kΩ at 1 kHz in electrochemical impedance spectroscopy measurements under physiological conditions. We investigated the maximum compression force of the 3D structures, which could withstand approximately 0.6 N per pillar. The 3D microelectrode arrays were used to record extracellular signals from HL-1 cells in culture as a proof of principle. Our results show regular firing of action potentials recorded at the tip of the 3D structures, demonstrating the possibility of recording cell signals in non-planar environments.
微电极阵列通常用于研究细胞的电生理行为。近年来，人们对制造三维微电极阵列的兴趣与日俱增。在此，我们展示了一种借助激光图案化技术快速制造基于环氧树脂的三维微电极阵列平台的新方法。为此，我们使用基于环氧树脂的干膜将三维柱光图案化为支架。通过对三维结构顶部溅射的铂膜进行激光图案化来制造电极和导体迹线，随后沉积聚对二甲苯-C进行绝缘。使用垂直激光烧蚀工艺暴露三维结构尖端的微电极。在生理条件下的电化学阻抗谱测量中，最终电极在1 kHz时显示出约10 kΩ的低阻抗。我们研究了三维结构的最大压缩力，每个柱可承受约0.6 N的力。作为原理验证，三维微电极阵列用于记录培养的HL-1细胞的细胞外信号。我们的结果显示在三维结构尖端记录到规则的动作电位发放，证明了在非平面环境中记录细胞信号的可能性。
