Strain Localization in Composite Inks and its Effect on Electrical Behavior under Monotonic and Cyclic Stretching

复合油墨中的应变局域化及其对单调和循环拉伸下电行为的影响

• 批准号: 2026936
• 负责人: Antonia Antoniou
• 金额: $ 49.14万
• 依托单位: Georgia Tech Research Corporation
• 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: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2026936&HistoricalAwards=false
• 关键词: Strain; Localization; Composite; Inks; its

Flexible electronics offer tantalizing potential in health and environmental monitoring. A crucial component of these devices is the electrical connection provided by conductive inks consisting of metallic flakes embedded in a flexible elastomer. Such composite connectors must remain conductive even after repetitive loading, such as stretching. Presently, there is limited knowledge of how the resistance to current flow is affected by cyclic loading. There is also little understanding of the causes of catastrophic failure of the conductor, which is essential for life-critical applications where current flow may be interrupted. This award seeks to establish an understanding of the mechanical and electrical response under cyclic loading for conductive composite inks through experiments and models. This effort can guide design of stretchable electronics and ensure reliability of such devices in a range of applications including health monitoring. The award also supports development of new class-based projects in undergraduate and graduate courses for both on campus and remote learning students. Additionally, wearable electronics learning modules will be developed for middle schoolers in the local counties with large underrepresented minority populations.The objective of this work is to obtain a fundamental understanding of the relationship between mechanical and electrical behavior of metal-polymer composite inks for wearable and stretchable applications when subjected to monotonic and cyclic loading, with a specific focus on strain localization. It is intuitive to assume that localized deformation dictates the evolution of the conductive percolation network and affects the resulting resistance. In-situ scanning electron microscopy and optical confocal microscopy, as well as focused ion beam sectioning will be used to understand the mechanistic origins of strain localization and quantify its evolution under various loading conditions. These experiments will also produce datasets on the statistical distribution of metallic flakes and voids, which will be used to understand the evolution of the percolating network. Several flexible and stretchable inks will be investigated based on material properties, defect distribution, and flake volume fraction. Lastly, an existing percolation model will be enhanced with spatiotemporal descriptions of these distributions to produce complementary data, predict electrical resistance evolution, and provide composite ink design guidelines.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.

柔性电子产品在健康和环境监测方面具有诱人的潜力。这些设备的一个重要组成部分是由嵌入柔性弹性体中的金属薄片组成的导电油墨提供的电气连接。即使在重复负载（例如拉伸）之后，此类复合连接器也必须保持导电性。目前，对于循环负载如何影响电流阻力的了解有限。人们对导体灾难性故障的原因也知之甚少，而这对于电流可能中断的生命攸关的应用至关重要。该奖项旨在通过实验和模型建立对导电复合油墨在循环负载下的机械和电气响应的理解。这项工作可以指导可拉伸电子产品的设计，并确保此类设备在包括健康监测在内的一系列应用中的可靠性。该奖项还支持为校园和远程学习的学生开发本科生和研究生课程中的新的基于课堂的项目。此外，还将为当地少数族裔人口较多的县的中学生开发可穿戴电子学习模块。这项工作的目的是对可穿戴和可拉伸应用的金属聚合物复合油墨在承受单调和循环载荷时的机械和电气行为之间的关系有一个基本的了解，特别关注应变局部化。直观地假设局部变形决定了导电渗流网络的演变并影响最终的电阻。原位扫描电子显微镜和光学共焦显微镜以及聚焦离子束切片将用于了解应变局部化的机械起源并量化其在各种负载条件下的演变。这些实验还将产生有关金属薄片和空隙统计分布的数据集，这些数据集将用于了解渗透网络的演变。将根据材料特性、缺陷分布和薄片体积分数研究几种柔性和可拉伸墨水。最后，现有的渗透模型将通过这些分布的时空描述得到增强，以产生补充数据，预测电阻演变，并提供复合墨水设计指南。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Trace width effects on electrical performance of screen-printed silver inks on elastomeric substrates under uniaxial stretch

• DOI: 10.1063/5.0056117
• 发表时间: 2021-09
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: G. Cahn;O. Pierron;A. Antoniou

Origins of strain localization in a silver-based flexible ink under tensile load

• DOI: 10.1088/2058-8585/ac414c
• 发表时间: 2021-12
• 期刊: Flexible and Printed Electronics
• 影响因子: 3.1
• 作者: Qiushi Li;O. Pierron;A. Antoniou

Understanding resistance increase in composite inks under monotonic and cyclic stretching

• DOI: 10.1088/2058-8585/aca98a
• 发表时间: 2022-12
• 期刊: Flexible and Printed Electronics
• 影响因子: 3.1
• 作者: Qiushi Li;Antonia Antoniou;Olivier N Pierron

Electrical performance evolution and fatigue mechanisms of silver-filled polymer ink under uniaxial cyclic stretch

• DOI: 10.1088/2058-8585/ac1243
• 发表时间: 2021
• 期刊: Flexible and Printed Electronics
• 影响因子: 3.1
• 作者: G. Cahn;O. Pierron;A. Antoniou

Modeling resistance increase in a composite ink under cyclic loading

• DOI: 10.1088/2058-8585/acbaab
• 发表时间: 2023-02
• 期刊: Flexible and Printed Electronics
• 影响因子: 3.1
• 作者: Qiushi Li;Euichul Chung;Antonia Antoniou;Olivier N Pierron