Improving the Resolution of 3D-Printed Molds for Microfluidics by Iterative Casting-Shrinkage Cycles
Improving the Resolution of 3D-Printed Molds for Microfluidics by Iterative Casting-Shrinkage Cycles
复制标题
通过迭代铸造收缩循环提高微流体 3D 打印模具的分辨率
DOI：
10.1021/acs.analchem.6b05148
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发表时间：
2017
影响因子：
7.4
通讯作者：
Eijkel Jan C. T.
中科院分区：
文献类型：
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作者：
Sun Miao;Xie Yanbo;Zhu Jihong;Li Jun;Eijkel Jan C. T.
突破技术壁垒和降低成本是微流控器件发展的关键问题，都很大程度上依赖于制造技术的创新和新材料的使用。 3D打印的应用以其多功能性和功能性无疑加速了微流控芯片的原型制作。然而，现有3D打印技术的分辨率仍远低于光刻技术，这使得其很难在单细胞规模上进行工作，并且几乎不可能在单分子规模上进行工作。在本文中，我们提出了一种通过聚氨酯 (PU) 聚合物的铸造收缩循环将 3D 打印微结构的分辨率提高到最低 4 μm 的简单方法。将水与 PU 液体混合物倒在 3D 打印模板上，快速固化复制结构，然后在溶剂蒸发后等轴收缩至其尺寸的一半，从而缩小复制结构的尺寸。通过重复铸造收缩循环，我们可以根据需要缩小 3D 打印结构的（亚）毫米结构，直到达到聚合物性能所造成的工作极限，我们通过制造微混合器来证明这一点。此外，我们甚至可以用毫米级的手工组装模板来制造微流控芯片，完全独立于任何微加工设备，大大降低了技术壁垒和成本，从而将微流控领域向资源匮乏的地区开放。
Breaking through technical barriers and cost reduction are critical issues for the development of microfluidic devices, and both rely greatly on the innovation of fabrication techniques and use of new materials. The application of 3D printing definitely accelerated the prototyping of microfluidic chips by its versatility and functionality. However, the resolution of existing 3D printing techniques is still far below that of lithography, which makes it difficult to work on the scale of single cells and near impossible for single molecule work. In this paper, we present a facile way to increase the resolution of 3D printed microstructures to minimally 4 μm by casting-shrinkage cycles of a polyurethane (PU) polymer. A water–PU liquid mixture poured on a 3D printed template quickly solidifies replicating the structures, which then isometrically shrink to half its size after solvent evaporation, downscaling the replicated structures. By repeating the casting-shrinkage cycles, we could downscale the (sub)millimeter structures of 3D printed structures on demand, until the working limit posed by the polymer properties, which we demonstrate by fabricating a micromixer. Moreover, we can even fabricate microfluidic chips from millimeter-scale manually assembled templates, fully independent of any micromachining facilities, significantly reducing the technical barriers and costs, thus opening up the microfluidics field to low-resource areas.