Department of Electrical and Electronic Engineering (DIEE), University of Cagliari, Via Marengo 3, 09123, Cagliari, Italy. Author to whom any correspondence should be addressed.
J Neural Eng. 2020 Jul 3;17(3):036033. doi: 10.1088/1741-2552/ab9844.
In this paper, we report on the development of an easy-to-fabricate three-dimensional Micro-Electrode Array (3D-MEA) specifically designed for brain-on-a-dish applications.
The proposed device consists of pillar-shaped gold microelectrodes realized by electroplating directly on top of a standard MEA, making this approach highly versatile and convenient for batch fabrication. Moreover, with this simple technique, it is possible to obtain electrodes with a height of more than 100 µm onto different kind of substrates, ranging from glass to flexible plastic ones.
This novel 3D-MEA structure has been validated with acute brain slices, successfully recording both epileptiform-like discharges (upon the administration of 4-AP), and electrically-evoked neuronal activity. The preliminary validation showed a substantial improvement in the signals amplitude with respect to both commercial and custom planar electrodes thanks to a better coupling offered by the peculiar shape of the three-dimensional electrodes.
Beside the versatility of the fabrication approach, which allows to obtain 3D MEA devices onto both rigid and flexible substrates, the reported validation showed how the pillar approach can outperform standard planar MEA recordings in terms of signal amplitude. Moreover, thanks to the possibility of obtaining multi-level 3D structures within the same device, the proposed fabrication technique offers an interesting and flexible approach for the development of a new family of electrophysiological tools for 3D in vitro electrophysiology, in particular for acute brain slices and 3D neuronal cultures for brain-on-a-dish applications.
本文介绍了一种易于制造的三维微电极阵列（3D-MEA）的开发，该阵列专门用于脑片上的应用。
所提出的器件由柱状金微电极组成，通过直接电镀在标准 MEA 上实现，这种方法非常通用，便于批量制造。此外，通过这种简单的技术，可以在不同类型的基底上获得超过 100 µm 高的电极，基底范围从玻璃到柔性塑料。
这种新颖的 3D-MEA 结构已通过急性脑片进行了验证，成功记录了 4-AP 给药后的癫痫样放电和电诱发的神经元活动。初步验证表明，与商业和定制平面电极相比，由于三维电极的特殊形状提供了更好的耦合，信号幅度有了实质性的提高。
除了制造方法的通用性之外，该方法允许在刚性和柔性基底上获得 3D MEA 器件，所报道的验证表明，在信号幅度方面，柱状方法可以优于标准平面 MEA 记录。此外，由于可以在同一器件中获得多级 3D 结构，所提出的制造技术为开发用于 3D 体外电生理学的新型电生理工具提供了一种有趣且灵活的方法，特别是用于脑片上的急性脑片和 3D 神经元培养。
