Polydimethylsiloxane (PDMS) microfluidic devices have become a standard tool for engineering cells and multicellular networks in vitro. However, the reservoirs, or through-holes where cells access the devices, are usually fabricated manually using a biopsy punch, making it difficult to create a large-scale array of small (<1 mm) reservoirs. Here, we present a fabrication process for a thin-film microfluidic device, or a microfluidic film ({\mu}FF), containing an array of through-holes. Holes as small as 100 {\mu}m by 100 {\mu}m spanning 10 mm by 10 mm are characterized. The geometry of the through-holes was precisely defined by the photoresist mould. A challenge in using the {\mu}FF for cell culture was air-bubble entrapments in the through-holes, which became more prominent with smaller holes. We show that this issue can be overcome using ethanol-mediated wetting of the PDMS surface, and demonstrate functional recording of cultured neuronal networks grown in {\mu}FFs. This technology opens new application of microfluidic devices to mesoscale systems comprised of several tens to hundreds of cells.

中文翻译：

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用于小规模神经元网络体外工程的聚二甲基硅氧烷微流体薄膜

聚二甲基硅氧烷 (PDMS) 微流体装置已成为体外工程细胞和多细胞网络的标准工具。然而，水库，或细胞进入设备的通孔，通常是使用活检打孔器手动制造的，因此很难创建小 (<1 毫米) 水库的大规模阵列。在这里，我们提出了一种薄膜微流体装置或微流体薄膜 ({\mu}FF) 的制造工艺，其中包含一系列通孔。小至 100 {\mu}m × 100 {\mu}m 的孔洞跨越 10 mm × 10 mm 是特征化的。通孔的几何形状由光刻胶模具精确定义。使用 {\mu}FF 进行细胞培养的一个挑战是通孔中的气泡截留，随着孔较小，气泡截留变得更加突出。我们表明可以使用乙醇介导的 PDMS 表面润湿来克服这个问题，并展示了在 {\mu}FFs 中生长的培养神经元网络的功能记录。这项技术开启了微流体装置在由数十到数百个细胞组成的中尺度系统中的新应用。