Electric Field Guided Micro Additive Manufacturing Process

具有微米和亚微米尺寸特征的产品在电子、生物医学、航空和能源工业中找到了广泛的应用，以提高效率和功能，然而现有技术在产生具有所需特征的复杂结构的能力方面受到限制。该项目的目标是实现一种新的微增材制造工艺，其中电场引导颗粒沉积成三维结构。该工艺的特点是微米级的分辨率，广泛的材料选择，和优越的上级处理时间。这项工作的科学发现也可能有助于克服与接触处理微组件相关的挑战，并为非接触式微组装提供新的工具。这项跨学科研究将促进培养新一代工程师和科学家，他们在现代微型制造科学和技术方面具有广泛而深入的知识，这将对美国经济产生衍生影响。该技术方法基于电泳沉积的使用，其中外部施加的电场控制分散颗粒在溶剂中的移动、团聚和沉积，而不需要昂贵且复杂的工具和加工设备。本研究将通过完成以下任务提供建立新的微增材制造技术所需的知识：在具有微电极阵列的介电泳沉积过程中创建用于粒子轨迹的力场控制的可靠模型;理解介电泳沉积的沉积阶段中粒子的引导自组装背后的基本物理;建立数值模型来表征电场对已经沉积的结构的稳定性的影响;以及在实验室规模的原型系统上验证所开发的模型。力场的控制将基于扩展有效场方法，该方法基于修正的能斯特-普朗克方程，以考虑粒子和粒子电荷浓度。粒子粘附到衬底表面和连续的自组织力学将被建模为电荷重新分配和能量最小化问题，分别。一个流线型的数值模型，在新的层沉积过程中的颗粒层的结构稳定性将被实施，以表征作为一个新的沉积表面的沉积层。数值模型将有助于优化电极几何形状和电极阵列拓扑结构，以提高工艺精度、构建的可重复性和电极耐用性。

Products with micron- and sub-micron-sized features find widespread applications in the electronic, biomedical, aeronautics, and energy industries for enhanced efficiency and functionality, yet existing techniques are limited in their ability to generate complex structures with the required features. The goal of this project is to enable a new micro-additive manufacturing process in which an electric field guides the deposition of particles into three-dimensional structures. The process is characterized by micron-level resolution, wide material selection, and superior processing time. The scientific findings of this work can also potentially contribute to overcoming challenges related to contact handling of micro-components and offer a new tool for contactless micro-assembly. This interdisciplinary research will promote the training of new generations of engineers and scientists with broad and deep knowledge in modern micro-manufacturing science and technology, which will have derivative effects on the US economy. The technical approach is based on the use of electrophoretic deposition in which an externally applied electric field governs the movement, agglomeration, and deposition of dispersed particles in a solvent, without requiring expensive and complex tooling and processing equipment. This research will provide the knowledge needed to establish the new micro additive manufacturing technology by completing the following tasks: creating reliable models for force field control of particle trajectories in a dielectrophoretic deposition process with arrays of micro electrodes; understanding the underlying physics behind the guided self-assembly of the particles in the deposition phase of the dielectrophoretic deposition; establishing a numerical model to characterize the influence of the electric field on the already deposited structure's stability; and verifying the developed model on a laboratory-scale prototyping system. The control of the force field will be based on an extended effective field method that is based on the modified Nernst-Planck equations to account for particle and particle charge concentration. Particle adhesion to the substrate surface and consecutive self-organization mechanics will be modeled as an electric charge redistribution and energy minimization problem, respectively. A streamlined numerical model for structural stability of the particle layer during new layer deposition will be implemented to characterize the deposited layer as a new deposition surface. The numerical models will facilitate the optimization of the electrode geometry and electrode array topology with respect to process accuracy, repeatability of the builds, and electrode durability.