Neuroelectronics - Munich School of Bioengineering, Department of Electrical and Computer Engineering , Technical University of Munich , Boltzmannstrasse 11 , 85748 Garching , Germany.
Institute of Complex Systems, Bioelectronics (ICS-8) , Forschungszentrum Jülich , 52425 Jülich , Germany.
ACS Appl Mater Interfaces. 2019 Sep 11;11(36):32778-32786. doi: 10.1021/acsami.9b11774. Epub 2019 Aug 29.
Microelectrode arrays (MEAs) are widely used platforms in bioelectronics to study electrogenic cells. In recent years, the processing of conductive polymers for the fabrication of three-dimensional electrode arrays has gained increasing interest for the development of novel sensor designs. Here, additive manufacturing techniques are promising tools for the production of MEAs with three-dimensional electrodes. In this work, a facile additive manufacturing process for the fabrication of MEAs that feature needle-like electrode tips, so-called μ-needles, is presented. To this end, an aerosol-jet compatible PEDOT:PSS and multiwalled carbon nanotube composite ink with a conductivity of 323 ± 75 S m is developed and used in a combined inkjet and aerosol-jet printing process to produce the μ-needle electrode features. The μ-needles are fabricated with a diameter of 10 ± 2 μm and a height of 33 ± 4 μm. They penetrate an inkjet-printed dielectric layer to a height of 12 ± 3 μm. After successful printing, the electrochemical properties of the devices are assessed via cyclic voltammetry and impedance spectroscopy. The μ-needles show a capacitance of 242 ± 70 nF at a scan rate of 5 mV s and an impedance of 128 ± 22 kΩ at 1 kHz frequency. The stability of the μ-needle MEAs in aqueous electrolyte is demonstrated and the devices are used to record extracellular signals from cardiomyocyte-like HL-1 cells. This proof-of-principle experiment shows the μ-needle MEAs' cell-culture compatibility and functional integrity to investigate electrophysiological signals from living cells.
微电极阵列 (MEA) 是生物电子学中广泛使用的平台，用于研究发电细胞。近年来，为了开发新型传感器设计，用于制造三维电极阵列的导电聚合物的处理得到了越来越多的关注。在这里，增材制造技术是生产具有三维电极的 MEA 的有前途的工具。在这项工作中，提出了一种用于制造具有所谓 μ-针电极尖端的 MEA 的简便增材制造工艺。为此，开发了一种与气溶胶喷射兼容的 PEDOT:PSS 和多壁碳纳米管复合油墨，其电导率为 323 ± 75 S m，并在喷墨和气溶胶喷射印刷工艺中使用该油墨来生产 μ-针电极特征。μ-针的直径为 10 ± 2 μm，高度为 33 ± 4 μm。它们穿透喷墨印刷的介电层的高度为 12 ± 3 μm。成功打印后，通过循环伏安法和阻抗谱评估器件的电化学性能。μ-针在扫描速率为 5 mV s 时表现出 242 ± 70 nF 的电容，在 1 kHz 频率时表现出 128 ± 22 kΩ 的阻抗。证明了 μ-针 MEA 在水基电解质中的稳定性，并使用该器件记录心肌细胞样 HL-1 细胞的细胞外信号。该原理验证实验表明 μ-针 MEA 具有细胞培养相容性和功能完整性，可用于研究活细胞的电生理信号。
