Coalescence of sessile droplets driven by electric field in the jetting-based 3D printing framework
Coalescence of sessile droplets driven by electric field in the jetting-based 3D printing framework
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DOI：
10.1007/s00348-021-03153-3
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发表时间：
2021-03-01
影响因子：
2.4
通讯作者：
Yarin, A. L.
中科院分区：
文献类型：
--
作者：
Plog, J.;Jiang, Y.;Yarin, A. L.
最近的发展表明，应用于3D打印（增材制造）的液滴喷射技术将成为创建生物传感器和可穿戴柔性三维电子设备的战略工具。虽然典型的离散形成的液滴往往会限制吞吐量，但喷射过程的几个亮点包括墨水/基材组合的丰富选择和几乎零浪费的打印。从功能制造的角度来看，重要的是要了解这些离散形成的液滴如何在所涉及的物理和硬件的限制内互连成数字图案化的线和膜。在这里，我们调查的有效性库仑力所产生的充电电极放置在基板下方或打印头上。从物理的角度来看，动态电润湿现象的介质（DEWOD）的使用。它表明，固着液滴，最初单独放置的自然聚结的机会很少，可以选择性地胁迫通过添加电场到电增强强制聚结。两种电极配置的间隔距离均大于文献中的结果。这些结果揭示了电驱动聚结的新表现，这为新的制造设计机会、减少原材料使用、在极其粗糙的表面上操作以及在以前的方法失败的情况下连续窄打印带来了巨大的希望。除了液滴成线聚结，第一近似潜力合并成膜的二维液滴阵列也被证明。
The recent developments revealed droplet jetting technologies, as applied to 3D printing (additive manufacturing), to be a strategic tool in creating biological sensors and wearable, flexible three-dimensional electronic devices. While the typical discretely formed droplets tend to limit throughput, several highlights to the jetting process include an ample choice of ink/substrate combinations and printing with nearly zero waste. From a functional manufacturing perspective, it is important to understand how these discretely formed droplets can be interconnected into digitally patterned lines and films within the limitations of the physics and hardware involved. Here, we investigate the effectiveness of a Coulomb force created by charged electrodes placed either below the substrate or on the printhead. From the physical point of view, the phenomenon of dynamic electrowetting-on-dielectric (DEWOD) is used. It is demonstrated that sessile droplets, placed initially separately with little chance of natural coalescence, can be selectively coerced by the added electric field into the electrically enhanced forced coalescence. Positive results were recorded for both electrode configurations at spacing distances greater than those achieved in literature. These results reveal novel manifestations of electrically driven coalescence, which hold great promise for new manufacturing design opportunities, reduction in raw material use, operation on extremely rough surfaces, and continuous narrow prints in situations where the previous approaches failed. In addition to droplet-into-line coalescence, the first-approximation potential to merge 2D droplet arrays into films is also demonstrated.