Kang Kyunghun, Oh Sangwoo, Yi Hak, Han Seungoh, Hwang Yongha
Department of ElectroMechanical Systems Engineering, Korea University, Sejong 30019, South Korea.
Maritime Safety Research Division, Korea Research Institute of Ships and Ocean Engineering, Daejeon, South Korea.
Biomicrofluidics. 2018 Jan 5;12(1):014105. doi: 10.1063/1.5012548. eCollection 2018 Jan.
The field of complex microfluidic channels is rapidly expanding toward channels with variable cross-sections (i.e., beyond simple rounded channels with a constant diameter), as well as channels whose trajectory can be outside of a single plane. This paper introduces the use of three-dimensional (3D) printed soluble wax as cast molds for rapid fabrication of truly arbitrary microfluidic polydimethylsiloxane (PDMS) channels that are not achieved through typical soft lithography. The molds are printed directly from computer-aided design files, followed by simple dissolution using a solvent after molding PDMS, making rapid prototyping of microfluidic devices possible in hours. As part of the fabrication method, the solubility of several build materials in solvents and their effect on PDMS were investigated to remove the 3D-printed molds from inside the replicated PDMS microfluidic channels without damage. Technology limits, including surface roughness and resolution by comparing the designed channels with fabricated cylindrical channels with various diameters, are also characterized. We reproduced a 3D image of an actual human cerebral artery as cerebral artery-shaped PDMS channels with a diameter of 240 m to prove the developed fabrication technique. It was confirmed that the fabricated vascular channels were free from any leakage by observing the fluorescence fluid fill.
复杂微流控通道领域正迅速朝着具有可变横截面的通道（即超出具有恒定直径的简单圆形通道）以及其轨迹可以在单个平面之外的通道发展。本文介绍了使用三维（3D）打印的可溶性蜡作为铸模，用于快速制造通过典型软光刻无法实现的真正任意形状的微流控聚二甲基硅氧烷（PDMS）通道。这些模具直接从计算机辅助设计文件打印出来，在模制PDMS后使用溶剂进行简单溶解，从而使微流控设备能够在数小时内快速成型。作为制造方法的一部分，研究了几种构建材料在溶剂中的溶解度及其对PDMS的影响，以便在不损坏复制的PDMS微流控通道内部的情况下移除3D打印的模具。还通过将设计的通道与制造的具有各种直径的圆柱形通道进行比较，表征了包括表面粗糙度和分辨率在内的技术限制。我们将实际人类脑动脉的3D图像复制为直径240μm的脑动脉形状的PDMS通道，以证明所开发的制造技术。通过观察荧光液体填充，证实制造的血管通道没有任何泄漏。
