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.

增强表面功能特性的两种最常见的方法是通过微尺度纹理和化学涂层。由于目前的方法在同时应用这两种方法的能力方面受到限制，因此需要一种新的制造技术，以便可以在单个过程中进行表面改性。一个潜在的候选者是自聚焦电流体动力学微织构（SF-EMT）工艺。它使用电力来操纵用于以逐滴方式打印结构的喷墨，以通过利用先前沉积的液滴与打印射流之间的吸引力来产生多层纹理。可以使用各种油墨将不同的化学物质嵌入到印刷结构上。SF-EMT的潜力将通过印刷大规模露水收集器和微电容器阵列来展示。SF-EMT将以更低的制造成本为高性能表面、表面改性和微结构打开大门。它的简单性和多功能性将允许快速原型的表面纹理和图案与不同的化学。研究生和本科生的多学科研究机会将通过这个项目提供。现有的体制机制和计划将被利用，以通知和吸引代表性不足的少数民族到这些先进的制造业研究职位，并进一步增加在STEM相关的careers.The SF-EMT的实现需要了解一个新发现的自聚焦机制，通过该机制，喷气机被吸引到以前沉积的功能。实验和数值模拟相结合，以了解在印刷过程的不同阶段的动态，复杂的电荷和质量转移机制将进行研究。重点将放在理解珠在表面上和其他珠顶部的沉积，整个过程中溶剂的蒸发，以及电荷的消散。该方法的实现还需要配制新的聚合物油墨。通过利用数值模型来显著减少潜在的设计空间和待测试的油墨数量，将加快针对特定应用的油墨成分的调整。用于露水收集的油墨将用纳米添加剂和表面活性剂进行改性，以在沉积的珠粒上产生纳米皱纹和纹理，从而产生多尺度纹理。对于微型电容器阵列，将配制导电和介电油墨。最先进的测试平台，具有机器视觉，用于喷射位置控制、珠粒尺寸和溶剂蒸发的原位计量、受控湿度，将建立对工艺参数的精确计算机控制，以验证数值模型和进行工艺评估。该奖项反映了NSF的法定使命，并且通过使用基金会的知识价值和更广泛的影响进行评估，被认为值得支持的搜索.