Collaborative Research: Understanding Material Transfer Mechanisms in Corona-Enabled Contactless Electrostatic Printing of Binder-free Nano-/micro-Structures

印刷电子产品具有改变公共健康、国家安全和整个社会的潜力。制造创新对于实现低成本和可扩展的生产、提高印刷电子产品的性能和实现其广泛应用至关重要。然而，当前的打印技术在解决打印速度与打印分辨率和性能之间的权衡方面仍然面临长期的挑战。该奖项支持基础研究，以推进一种新型的电晕启用非接触式静电打印(CEP)技术，该技术利用超高速静电吸引现象来实现材料转移和大规模制造无粘结剂的纳米/微结构。非接触式力控制和无粘结剂特性减少了制造时间和温度，具有更广泛的材料选择，并具有操纵和组装纳米/微结构的能力，并提高了器件性能。CEP工艺的卷到卷兼容性也可能促进从基础研究过渡到商业市场的途径，潜在地有利于大面积和高性能电子产品以及灵活功能系统的多功能应用。通过一所R1大学和一所为少数族裔服务的机构以及另外一个工业合作伙伴的密切合作，该项目还为少数族裔本科生提供实践研究机会和工业经验，并为当地高中举办“未来电子”社区参与研讨会，旨在激励更多的学生和工程师参与并受益于蓬勃发展的美国电子行业，并为其做出贡献。为了推进CEP进程，该项目将通过数值和实验相结合的方法，专注于三个基础研究推进。首先，通过绘制电荷分布图和计算电场分布，揭示电场的形成和动态演化机理，这对于实现精确控制是必不可少的。然后，通过研究材料的电导率、几何形状和密度对CEP过程的影响，研究了CEP过程中的材料传递机理。该项目还将探索通过将电场与机械场相结合来制造定向纳米/微结构的方法。此外，通过同时监测印刷结构的微观结构演变和电性能，以及对无粘结剂CEP电子性能的影响，将研究印刷结构对外部刺激的响应机制。总体而言，对CEP过程的基本理解预计将大大增强精确控制电场以实现超快材料操纵、纳米/微结构构建和高端电子制造的能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Printed electronics have a potential to transform the public health, the national security, and society as a whole. Manufacturing innovations are essential to enable cost-effective and scalable production, enhance the performance of printed electronics, and realize their broad applications. Current printing techniques, however, still face long-lasting challenges in addressing the tradeoff between the printing speed versus the print resolution and performance. This award supports fundamental research to advance a novel corona-enabled contactless electrostatic printing (CEP) technique that utilizes the ultra-fast electrostatic attraction phenomenon to achieve the material transfer and manufacturing of binder-free nano-/micro-structures at a large scale. The contactless force control and binder-free nature lead to reduced manufacturing times and temperatures, with broader material options, and an ability to manipulate and assemble nano-/micro-structures, and improved device performance. The roll-to-roll compatibility of the CEP process may also facilitate a pathway for transition from fundamental research to commercial marketplaces, potentially beneficial to large-area and high-performance electronics and versatile applications of flexible functional systems. Through a close collaboration between an R1 university and a minority-serving institution, with additionally an industrial partner, this project also provides hands-on research opportunities and industrial experiences to minority undergraduate students and hosts “Future Electronics” community engagement workshops to local high schools, intended to inspire more students and engineers to participate in, benefit from, and contribute to the blooming U.S. electronics industry.To advance the CEP process, the project will focus on three basic research thrusts by a combination of numerical and experimental approaches. First, through mapping the distribution of charges and computing the distribution of the electric field, the formation and dynamic evolution mechanisms of the electric field will be revealed, which is essential to achieve precision controls. Then, the material transfer mechanism during the CEP process will be studied by investigating the impacts of the material conductivity, geometry and density. The project will also explore methodologies to manufacture aligned nano-/micro-structures by combining an electric field with a mechanical field. Further, the responsive mechanisms of the printed structures to external stimuli will be studied by monitoring the microstructure evolution and electrical performance simultaneously, together with the effects on the performance of the binder-free CEP electronics. Overall, the fundamental understanding of the CEP process is expected to substantially enhance the capability to precisely control an electric field to realize ultra-fast material manipulations, nano-/micro-structure constructions, and high-end electronics manufacturing.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.