3D Printed lattice microstructures to mimic soft biological materials.
3D Printed lattice microstructures to mimic soft biological materials.
复制标题
3D 打印晶格微结构来模拟软生物材料。
DOI：
10.1088/1748-3190/aae10a
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发表时间：
2018
影响因子：
3.4
通讯作者：
Rombokas,Eric
中科院分区：
文献类型：
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作者：
Johnson,LukeK;Richburg,Chris;Lew,Madelyn;Ledoux,WilliamR;Aubin,PatrickM;Rombokas,Eric
目的：本小组开发了一种3D打印机械逼真的软组织的方法，作为开发解剖逼真的3D打印生物力学试验台模型的基础。方法采用Polyjet 3D打印机打印晶格微结构，并对其进行压缩测试，评价其弹性轮廓。改变晶格性质，包括单元直径、单元间距、单元横截面几何形状、单元排列和晶格旋转，以确定它们对应力-应变曲线的影响。作为一个案例研究，单个3D打印样品被调整，使其弹性轮廓与足底脂肪相匹配。结果元件直径和ES对应力-应变曲线的影响最大，旋转晶格微观结构使应力-应变曲线趋于线性化。柱直径0.5 mm、柱间距1.2 mm的简单立方点阵圆柱体微结构，其应力-应变曲线最接近足底脂肪。在10%、30%和50%应变下的弹性模量分别为7.55、9.50和252 kPa。相同应变值下生理足底脂肪的模量分别为1.08、7.13和188 kPa。我们证明了晶格微结构可以使软3D打印材料的杨氏模量降低三个数量级。通过创建一种方法来微调3d打印材料的弹性轮廓，使其表现得像人类软组织一样，我们提供了一种有吸引力的替代方法，可以替代更奇特和耗时的技术，如成型和铸造。
ObjectiveOur group has developed a method for 3D printing mechanically-realistic soft tissue, as a building block towards developing anatomically realistic 3D-printed biomechanical testbed models.MethodsA Polyjet 3D printer was used to print lattice microstructures, which were tested in compression to evaluate the elastic profile. Lattice properties including element diameter, element spacing (ES), element cross-sectional geometry, element arrangement, and lattice rotation were varied to determine their effect on the stress–strain curve. As a case study, a single 3D printed sample was tuned such that its elastic profile matched plantar fat.ResultsElement diameter and ES had the largest effect on the stress–strain profile, and rotating the lattice microstructure tends to linearize the curves. A simple cubic lattice microstructure of cylindrical elements, with 0.5 mm diameter columns and 1.2 mm spacing had a stress–strain curve the was closest to plantar fat. The elastic modulus at 10, 30, and 50% strain was 7.55, 9.50, and 252 kPa respectively. Physiologic plantar fat at the same strain values has moduli values of 1.08, 7.13, and 188 kPa.SignificanceWe demonstrated that lattice microstructures can decrease the young's modulus of soft 3D printed materials by three orders of magnitude. By creating a method for fine-tuning the elastic profile of 3D-printed materials to behave like human soft tissue, we provide an attractive alternative to more exotic and time-consuming techniques such as molding and casting.