CAREER: Multi-Component Dispersions for Multi-Layer Additive Manufacturing

基于液滴的打印是一种增材制造工艺，其使用材料液滴作为构建块来形成二维和三维（2D和3D）物体。由于其高生产速度和精确放置各种有机和无机材料液滴的能力，这些类型的工艺已被采用在各种重要的应用中。然而，目前用于基于液滴的印刷的油墨在很大程度上限于单一材料。因此，缩放到由多种材料组成的多层结构需要用于每种材料的附加打印头和顺序地存款每种材料层的附加时间，使得单打印头方法成本过高且耗时。这个教师早期职业发展（CAREER）项目将探索开发多组分分散液和相应的沉积顺序的原则，用于通过利用新的自组装工艺，使用单一油墨以液滴为基础制造多材料，多层薄膜。这种复合膜，结合了各种各样的有机和无机材料，越来越多地发现在不同的领域，如电子，能源设备，光学和机械涂层，生物材料和药物的应用。这种跨学科的研究结合了制造，化学，材料科学，控制和机器学习的各个方面。沿着利用创新学习模式的推广计划，这将有助于扩大代表性不足的群体在研究中的参与，并对工程教育产生积极影响。多组分分散体可以实现更实用的方法，以液滴为基础制造多材料，多层结构。然而，缺乏关于将多个组分引导成期望的多层结构所需的化学和热力学机制以及当沉积的液滴聚结以形成2D膜时所涉及的流体力学的知识。为了填补这一空白，研究小组将开发一个综合的理论，实验和计算框架，用于快速确定多组分分散体组合物和制造所需多层形态薄膜所需的后续印刷程序。特别是，研究小组将利用建模，计算和表征技术的组合，以了解1）形成多层多材料沉积物所需的溶剂，颗粒和聚合物热力学关系，2）溶剂/颗粒/聚合物化学和浓度对层厚度的影响，存款形成动力学，以及干燥液滴的多层存款形态，以及3）墨滴间距和沉积顺序对沉积墨滴之间的油墨迁移以及由此产生的2D薄膜形态的影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Droplet-based printing is an additive manufacturing process that uses droplets of materials as building blocks to form two and three dimensional (2D and 3D) objects. Because of their high production speeds and ability to precisely place droplets of various organic and inorganic materials, these types of processes have been adopted in a variety of important applications. However, current inks used in droplet-based printing are largely limited to a single material. As such, scaling to multi-layer structures comprised of multiple materials requires an additional printhead for each material and additional time to sequentially deposit each material layer, making single printhead approaches prohibitively costly and time consuming. This Faculty Early Career Development (CAREER) project will explore principles for developing multi-component dispersions and corresponding deposition sequences for droplet-based manufacturing of multi-material, multi-layer films using a single ink by leveraging a new self-assembly process. Such complex films, incorporating a wide variety of organic and inorganic materials, are increasingly finding application in diverse areas such as electronics, energy devices, optical and mechanical coatings, biological materials, and pharmaceuticals. This interdisciplinary research combines aspects of manufacturing, chemistry, materials science, controls, and machine learning. Along with an outreach program leveraging innovative modes of learning, this will help broaden participation of underrepresented groups in research and positively impact engineering education.Multi-component dispersions could enable more practical approaches to droplet-based manufacturing of multi-material, multi-layer structures. However, there is a dearth of knowledge regarding the chemical and thermodynamic mechanisms necessary to guide multiple components into desired multi-layer structures and the fluid mechanics involved as the deposited droplets coalesce to form a 2D film. To fill this gap, the research team will develop a combined theoretical, experimental, and computational framework for the rapid determination of both the multi-component dispersion composition and the subsequent print routine needed to manufacture films of a desired multi-layer morphology. In particular, the research team will utilize a combination of modeling, computational, and characterization techniques to develop an understanding of 1) the solvent, particle, and polymer thermodynamic relationships necessary to form multi-layer multi-material deposits, 2) the effects of solvent/particle/polymer chemistry and concentration on layer thickness, deposit formation dynamics, and multi-layer deposit morphology of drying droplets, and 3) the effects of drop spacing and deposition sequence on migration of ink between deposited droplets and the resulting morphology of the 2D film.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.