This paper describes an innovative yet straightforward fabrication technique to create three-dimensional (3D) microstructures with controllable tapered geometries by combining conventional photolithography and thermal reflow of photoresist. Positive photoresist-based microchannel structures with varying width-to-length ratios were reflowed after their fabrication to generate 3D funnel structures with varying curvatures. A polydimethylsiloxane (PDMS) hourglass-shaped microchannel array was next cast on these photoresist structures, and primary human lung microvascular endothelial cells (HLMECs) were cultured in the device to engineer an artificial capillary network. Our work demonstrates that this cost-effective and straightforward fabrication technique has great potential in engineering 3D microstructures for biomedical and biotechnological applications such as blood vessel regeneration strategies, drug screening for vascular diseases, microcolumns for bioseparation, and other fluid dynamic studies at microscale.

中文翻译：

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由回流光刻胶结构制成的 3D 聚二甲基硅氧烷微沙漏形通道阵列，用于设计毛细血管网络

本文描述了一种创新而直接的制造技术，通过结合传统光刻和光刻胶热回流来创建具有可控锥形几何形状的三维 (3D) 微结构。具有不同宽长比的基于正光刻胶的微通道结构在制造后进行回流，以生成具有不同曲率的 3D 漏斗结构。接下来将聚二甲基硅氧烷 (PDMS) 沙漏形微通道阵列浇铸在这些光刻胶结构上，并在该装置中培养原代人肺微血管内皮细胞 (HLMEC) 以设计人工毛细血管网络。