Study of Layer Formation During Droplet-Based Three-Dimensional Printing of Gel Structures
Study of Layer Formation During Droplet-Based Three-Dimensional Printing of Gel Structures
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DOI：
10.1115/1.4036785
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发表时间：
2017-09
影响因子：
4
通讯作者：
Kyle Christensen;Yong Huang
中科院分区：
文献类型：
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作者：
Kyle Christensen;Yong Huang
增材制造，也被称为三维（3D）打印，是一种可以一层一层地制造结构的方法。对于3D喷墨打印，液滴从喷嘴喷射出来，每一层都是由液滴一滴形成的。喷墨打印已广泛应用于三维生物凝胶结构的制造，但对打印液滴之间的微尺度相互作用的了解仍然很大程度上难以捉摸。本研究旨在利用高速成像和粒子成像测速技术，从单线和相邻线组成的层在海藻酸盐滴按需喷墨打印过程中的形成机制来阐明层的形成机制。发现喷墨液滴在沉积部位的流体区域内撞击、扩散和凝聚，在一层内形成连贯的印刷线。在凝胶动力学的基础上，讨论了打印条件对层形成过程中液滴行为的影响，并提出了一些建议，以实现凝胶结构的可控和可靠制造。在海藻酸盐打印过程中，凝胶对液滴冲击动力学的影响可以忽略不计，并且发现根据打印条件，打印路径方向和凝胶动力学，在一层内的打印线之间形成界面。
Additive manufacturing, also known as three-dimensional (3D) printing, is an approach in which a structure may be fabricated layer by layer. For 3D inkjet printing, droplets are ejected from a nozzle, and each layer is formed droplet by droplet. Inkjet printing has been widely applied for the fabrication of 3D biological gel structures, but the knowledge of the microscale interactions between printed droplets is still largely elusive. This study aims to elucidate the layer formation mechanism in terms of the formation of single lines and layers comprised of adjacent lines during drop-on-demand inkjet printing of alginate using high speed imaging and particle image velocimetry. Inkjet droplets are found to impact, spread, and coalesce within a fluid region at the deposition site, forming coherent printed lines within a layer. The effects of printing conditions on the behavior of droplets during layer formation are discussed and modeled based on gelation dynamics, and recommendations are presented to enable controllable and reliable fabrication of gel structures. The effects of gelation on droplet impact dynamics are found to be negligible during alginate printing, and interfaces are found to form between printed lines within a layer depending on printing conditions, printing path orientation, and gelation dynamics.