Multi-Scale Multi-Material Printing of 3D Bead Arrays via Self-Focused Electrohydrodynamic Jets

通过自聚焦电流体动力喷射进行 3D 珠阵列的多尺度多材料打印

• 批准号: 1934350
• 负责人: Kornel Ehmann
• 金额: $ 44.47万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1934350&HistoricalAwards=false
• 关键词: Multi; Scale; Material; Printing; 3D

The two most common ways for enhancing the functional properties of a surface are through micro-scale texturing and chemical coatings. Since current methods are limited in their ability to apply both of these methods simultaneously, a novel manufacturing technique is required so that surface modifications can be done in a single process. One potential candidate is a Self-Focused Electrohydrodynamic Micro-Texturing (SF-EMT) process. It uses electric force to manipulate an ink jet for printing structures in a droplet-by-droplet fashion to produce multilayer textures by utilizing the attraction between the previously deposited droplets and the printing jet. A variety of inks can be used to embed different chemistries on the printed structure. The potential of SF-EMT will be demonstrated by printing large-scale dew-collectors and micro-capacitor arrays. SF-EMT will open doors to high-performance surfaces, surface modifications and micro-structures at reduced manufacturing costs. Its simplicity and versatility will allow for rapid prototyping of surface textures and patterns with varying chemistries. Multidisciplinary research opportunities for graduate and undergraduate students will be made available through this project. Existing institutional mechanisms and programs will be leveraged to inform and attract underrepresented minorities to these advanced manufacturing research positions, and to further increase interest in STEM related careers.The realization of SF-EMT requires the understanding of a newly discovered self-focusing mechanism by which the jet is attracted to previously deposited features. A combination of experiments and numerical modeling to understand the dynamic, complex charge and mass transfer mechanisms at the different stages of the printing process will be investigated. Emphasis will be on understanding the deposition of beads on a surface and on top of other beads, the evaporation of the solvent throughout the process, and the dissipation of electrical charges. The realization of the process also requires the formulation of new polymeric inks. Tuning of ink composition for the specific applications will be expedited by leveraging the numerical models to significantly reduce the potential design space and the number of inks to be tested. Inks for dew-collection will be modified with nano-additives and surfactants to create nano-wrinkles and texture on the deposited beads resulting in multi-scale textures. For micro-capacitor arrays, conductive and dielectric inks will be formulated. A state-of-the-art testbed with machine vision for jet position control, in-situ metrology of bead size and solvent evaporation, controlled humidity, and precise computer control of the process parameters will be built for validation of the numerical models and for process assessment.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.

增强表面功能性能的两种最常见方法是通过微尺度纹理和化学涂层。由于当前方法的同时应用这两种方法的能力受到限制，因此需要一种新型的制造技术，以便可以在单个过程中进行表面修改。一个潜在的候选者是自我关注的电水动力学微型纹理（SF-EMT）过程。它使用电力来操纵墨水喷气机，以逐滴的方式打印结构，以利用先前沉积的液滴和印刷射流之间的吸引力来产生多层纹理。各种墨水可用于将不同的化学物质嵌入印刷结构上。 SF-EMT的潜力将通过打印大规模露水收集器和微电容器阵列来证明。 SF-EMT将在降低的制造成本下为高性能表面，表面修饰和微结构打开大门。它的简单性和多功能性将允许与化学成分不同的表面纹理和图案进行快速原型。该项目将为研究生和本科生提供多学科研究机会。现有的机构机制和计划将被利用，以告知和吸引代表性不足的少数群体进入这些先进的制造研究职位，并进一步增加对STEM相关职业的兴趣。SF-EMT的实现需要了解新发现的自我关注的机制，通过该机制将喷气机通过该机制吸引到先前沉积的特征。将研究实验和数值建模的组合，以了解印刷过程不同阶段的动态，复杂的电荷和传质机制。重点是理解珠子在表面和其他珠的顶部的沉积，整个过程中溶剂的蒸发以及电荷的耗散。该过程的实现还需要制定新的聚合物油墨。通过利用数值模型显着减少潜在的设计空间和要测试的油墨的数量来加快针对特定应用的墨水组合物的调整。用于露水收集的油墨将使用纳米添加剂和表面活性剂修饰，以在沉积的珠子上产生纳米 - 扭曲和质地，从而产生多尺度的质地。对于微电容器阵列，将制定导电和介电墨水。将建立一个最先进的测试，该测试贴有机器视觉控制，对珠子大小和溶剂蒸发，控制湿度的原位计量学，对流程参数的精确计算机控制进行验证，以验证数值模型和过程评估。该奖项通过评估了NSF的法规范围，反映了对概念的支持。