A Computational Fluid Dynamics Investigation of Pneumatic Atomization, Aerosol Transport, and Deposition in Aerosol Jet Printing Process
A Computational Fluid Dynamics Investigation of Pneumatic Atomization, Aerosol Transport, and Deposition in Aerosol Jet Printing Process
复制标题
DOI：
10.1115/1.4049958
复制
发表时间：
2021-03-01
影响因子：
1
通讯作者：
Poliks, Mark D.
中科院分区：
文献类型：
--
作者：
Salary, Roozbeh (Ross);Lombardi, Jack P.;Poliks, Mark D.
气溶胶喷射印刷（AJP）是一种直写增材制造技术，其已经成为用于制造广谱电子设备的高分辨率方法。尽管AJP在印刷电子工业中具有优势和关键应用，但AJP工艺本质上是不稳定的，复杂的，并且容易出现意想不到的逐渐漂移，这对印刷电子器件的形态产生不利影响，从而影响其功能性能。因此，在AJP现场过程监测和控制是一个必然的需要。在这方面，除了AJP过程的实验表征之外，还需要物理模型来解释AJP中潜在的空气动力学现象。本研究工作的目标是建立一个基于物理的计算平台，用于预测气溶胶流态，并最终实现物理驱动的AJP过程控制。为了实现这一目标，我们的目标是提出一个三维（3D）可压缩，湍流，多相计算流体动力学（CFD）模型，以研究背后的空气动力学：（i）气溶胶的产生，（ii）气溶胶传输，和（iii）气溶胶沉积在一个移动的自由表面上的AJP过程。沉积头以及气动雾化器的复杂几何形状在ANSYS-FLUENT环境中建模，基于专利设计以及从3D X射线微计算机断层扫描（mu-CT）成像获得的精确测量。随后使用光滑和柔软的四边形元素的混合物对构建的几何形状的整个体积进行网格化，并考虑膨胀层以获得壁附近的精确解。采用基于密度和基于压力的Navier-Stokes形成的组合方法来获得稳态解并使守恒不平衡低于指定的线性化容差（即，10（-6））。湍流模型采用可实现的k-s粘性模型和可缩放的壁面函数。此外，还建立了一个两相流耦合模型来跟踪大量的注入颗粒。CFD模型的边界条件是根据AJP控制系统记录的实验传感器数据定义的。该模型的准确性进行了验证，使用析因实验，包括AJ-deposition的银纳米粒子墨水在聚酰亚胺基板上。本研究的结果为实施物理驱动的AJP现场监测和控制铺平了道路。
Aerosol jet printing (AJP) is a direct-write additive manufacturing technique, which has emerged as a high-resolution method for the fabrication of a broad spectrum of electronic devices. Despite the advantages and critical applications of AJP in the printed-electronics industry, AJP process is intrinsically unstable, complex, and prone to unexpected gradual drifts, which adversely affect the morphology and consequently the functional performance of a printed electronic device. Therefore, in situ process monitoring and control in AJP is an inevitable need. In this respect, in addition to experimental characterization of the AJP process, physical models would be required to explain the underlying aerodynamic phenomena in AJP. The goal of this research work is to establish a physics-based computational platform for prediction of aerosol flow regimes and ultimately, physics-driven control of the AJP process. In pursuit of this goal, the objective is to forward a three-dimensional (3D) compressible, turbulent, multiphase computational fluid dynamics (CFD) model to investigate the aerodynamics behind: (i) aerosol generation, (ii) aerosol transport, and (iii) aerosol deposition on a moving free surface in the AJP process. The complex geometries of the deposition head as well as the pneumatic atomizer were modeled in the ANSYS-FLUENT environment, based on patented designs in addition to accurate measurements, obtained from 3D X-ray micro-computed tomography (mu-CT) imaging. The entire volume of the constructed geometries was subsequently meshed using a mixture of smooth and soft quadrilateral elements, with consideration of layers of inflation to obtain an accurate solution near the walls. A combined approach, based on the density-based and pressure-based Navier-Stokes formation, was adopted to obtain steady-state solutions and to bring the conservation imbalances below a specified linearization tolerance (i.e., 10(-6)). Turbulence was modeled using the realizable k-s viscous model with scalable wall functions. A coupled two-phase flow model was, in addition, set up to track a large number of injected particles. The boundary conditions of the CFD model were defined based on experimental sensor data, recorded from the AJP control system. The accuracy of the model was validated using a factorial experiment, composed of AJ-deposition of a silver nanoparticle ink on a polyimide substrate. The outcomes of this study pave the way for the implementation of physics-driven in situ monitoring and control of AJP.