Optical Approach to Resin Formulation for 3D Printed Microfluidics.
Optical Approach to Resin Formulation for 3D Printed Microfluidics.
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DOI：
10.1039/c5ra23855b
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发表时间：
2015-12-31
期刊：
影响因子：
3.9
通讯作者：
Nordin GP
中科院分区：
文献类型：
--
作者：
Gong H;Beauchamp M;Perry S;Woolley AT;Nordin GP
与许多应用相比，微流体对3D打印提出了不同的要求，因为微流体的关键特征由内部微孔组成。然而，用于一般3D打印应用的树脂不一定是为了满足微流体的要求并最小化制造空隙的尺寸而配制的。在本文中，我们使用的光学方法来指导定制配方的树脂，以尽量减少制造的流动通道的横截面尺寸的例子，这样的空隙。我们专注于立体光刻（SL）3D打印，基于数字光处理（DLP）阵列，并使用商用3D打印机。我们开发了一个数学模型，用于通过3D打印部件的厚度传递的光学剂量，包括空隙的影响。我们发现，有一个基本的权衡之间的均匀性的光学剂量在各个层和多远的临界剂量渗透到一个流动通道在制造过程中。我们还实验性地研究了给定树脂的光学性质的流动通道小型化的实际限制，并且发现最小流动通道高度为~3.5-5.5ha，其中ha是树脂的光学穿透深度，并且最小宽度为构建平面中的4个像素。我们还表明，构建层厚度与ha的比率应在0.3-1.0的范围内，以获得给定树脂的最小流道高度。对于10 μm的构建层厚度，我们证明定制树脂的最小流道尺寸为60 μm × 108 μm。这项工作为<100 μm微流体特征的3D打印奠定了基础。
Microfluidics imposes different requirements on 3D printing compared to many applications because the critical features for microfluidics consist of internal microvoids. Resins for general 3D printing applications, however, are not necessarily formulated to meet the requirements of microfluidics and minimize the size of fabricated voids. In this paper we use an optical approach to guide custom formulation of resins to minimize the cross sectional size of fabricated flow channels as exemplars of such voids. We focus on stereolithgraphy (SL) 3D printing with Digital Light Processing (DLP) based on a micromirror array and use a commercially available 3D printer. We develop a mathematical model for the optical dose delivered through the thickness of a 3D printed part, including the effect of voids. We find that there is a fundamental trade-off between the homogeneity of the optical dose within individual layers and how far the critical dose penetrates into a flow channel during fabrication. We also experimentally investigate the practical limits of flow channel miniaturization given the optical properties of a resin and find that the minimum flow channel height is ~3.5–5.5ha where ha is the optical penetration depth of the resin, and that the minimum width is 4 pixels in the build plane. We also show that the ratio of the build layer thickness to ha should be in the range 0.3–1.0 to obtain the minimum flow channel height for a given resin. The minimum flow channel size that we demonstrate for a custom resin is 60 μm × 108 μm for a 10 μm build layer thickness. This work lays the foundation for 3D printing of <100 μm microfluidic features.