A Charge-Based Mechanistic Study into the Effects of Process Parameters on Fiber Accumulating Geometry for a Melt Electrohydrodynamic Process
A Charge-Based Mechanistic Study into the Effects of Process Parameters on Fiber Accumulating Geometry for a Melt Electrohydrodynamic Process
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DOI：
10.3390/pr8111440
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发表时间：
2020-11
期刊：
影响因子：
3.5
通讯作者：
K. Cao;Fucheng Zhang;R. Chang
中科院分区：
文献类型：
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作者：
K. Cao;Fucheng Zhang;R. Chang
熔融电流体动力学过程与可移动收集器相结合，具有广阔的工程组织应用前景。然而，纤维内的残留电荷会降低其打印保真度。为了阐明残余电荷发挥作用的机制并排除收集器运动的混杂效应，采用固定打印模式，其中纤维沉积在固定收集器上。本文研究了工艺参数对通用印刷结果的影响。纤维沉积物具有独特的形状特征，其特征是由外环包围的中心锥体，其特征在于其高度与基底直径 Hdep/Ddep 的比率。结果表明，Hdep/Ddep 随着集电极温度的增加而增加，并随着电压的增加而略有减少。此外，记录并分析了不同收集器温度下的稳态动态喷射沉积过程。基于电荷的偏振机制描述了收集器温度对纤维堆积形状的影响，这在纤维沉积的初始阶段和稳态阶段都很明显。因此，这项研究的一个关键成果是对集热器温度的识别和机理理解，作为一个可调节的过程变量，可以产生可预测的结构结果。这对于增材制造工艺应用（例如分层支架的熔融电写入）可能具有交叉潜力。
Melt electrohydrodynamic processes, in conjunction with a moveable collector, have promising engineered tissue applications. However, the residual charges within the fibers deteriorate its printing fidelity. To clarify the mechanism through which the residual charges play roles and exclude the confounding effects of collector movement, a stationary printing mode is adopted in which fibers deposit on a stationary collector. Effects of process parameters on generalizable printing outcomes are studied herein. The fiber deposit bears a unique shape signature typified by a central cone surrounded by an outer ring and is characterized by a ratio of its height and base diameter Hdep/Ddep. Results indicate Hdep/Ddep increases with collector temperature and decreases slightly with voltage. Moreover, the steady-state dynamic jet deposition process is recorded and analyzed at different collector temperatures. A charge-based polarization mechanism describing the effect of collector temperature on the fiber accumulating shape is apparent in both initial and steady-state phases of fiber deposition. Therefore, a key outcome of this study is the identification and mechanistic understanding of collector temperature as a tunable process variable that can yield predictable structural outcomes. This may have cross-cutting potential for additive manufacturing process applications such as the melt electrowriting of layered scaffolds.