CAREER: Manufacturing Soft Functional Composites through Mechanically Induced Assembly of Liquid Microstructures in Elastic Films

学院早期职业发展(Career)补助金支持研究，以了解管理液态金属基复合材料的连续制造和微结构组装的基本工艺-结构-性能关系，以实现一种新型的柔软、可变形和坚固的功能材料。由分散在弹性固体中的液态金属液滴组成的柔性功能复合材料在可自我修复和可拉伸的电子设备、软机器人和便携式设备的热接口材料方面显示出良好的性能。然而，这些复合材料往往是一批制得的，这限制了可伸缩性，而且液态金属夹杂物在制造过程中如何变形和组装的加工依赖和潜在机制尚不清楚。这项研究将确定基本的夹杂物变形机制，并量化软复合材料中液态金属组织在加工过程中的演变。通过调整加工过程中液态金属夹杂物的形态，这项研究有可能指导实现新的连续制造战略，以实现功能软材料的精确和高度可控的机械、电和热性能。通过这项研究获得的知识将使未来的电子和机器人技术创新成为可能，从而造福于国民经济和社会。此外，这项研究还与更广泛的外展计划和日营相结合，重点是弗吉尼亚州西南部的第一代学生。该推广计划旨在吸引、激发和发展学生对制造、软电子和机器人技术的兴趣和技能，同时突出STEM职业选择。研究的具体目标是确定液态金属夹杂物如何在软固体中变形和组装的加工依赖、潜在机制和定量微结构起源。这是通过控制处理策略的组合来实现的，例如薄膜压花、拉紧或拉伸，以及具有现场电气表征和同步微纳计算机断层扫描的卷对卷组装。这种方法通过机械诱导在弹性薄膜中组装液体微结构，提供了先进的软复合材料制造所需的工艺-结构-性能关系。该项目旨在确定液态金属夹杂物的基本变形机制和随之而来的微观结构作为夹杂物大小、形状和体积载荷的函数。通过在加工过程中控制液滴夹杂物的形状和连通性，通过可重构的微观结构，将创建具有可编程性能的软功能复合材料。该项目将为软弹性薄膜中液体结构的制造和组装提供见解，引入通过可重构液体微结构控制材料性能的新方向，并使软电子和机器人材料的设计和制造成为可能。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。

This Faculty Early Career Development (CAREER) grant supports research to understand the fundamental processing-structure-property relationships that govern continuous manufacturing and microstructural assembly of liquid metal-based composites for a new class of soft, deformable, and robust functional materials. Soft functional composites consisting of liquid metal droplets dispersed in elastic solids have shown promising capabilities for self-healing and stretchable electronics, soft robots, and thermal-interface materials for portable devices. However, these composites are often created in a single batch which limits scalability, and the processing dependence and underlying mechanisms of how liquid metal inclusions deform and assemble during manufacturing is not well known. This research will determine the fundamental inclusion deformation mechanisms and quantify how liquid metal microstructures in soft composites evolve during processing. This research has the potential to guide the realization of new continuous manufacturing strategies for precise and highly controlled mechanical, electrical, and thermal properties in functional soft materials by tuning liquid metal inclusion morphology during processing. The knowledge gained through this research will enable future innovations in electronics and robotics, which benefits national economy and society. Additionally, the research is paired with a broader outreach program and day camp, with an emphasis on first-generation students in Southwest Virginia. The outreach program is designed to engage, excite, and develop student interest and skills in manufacturing, soft electronics, and robotics while highlighting STEM career options.The specific goal of the research is to determine the processing dependence, underlying mechanisms, and quantitative microstructural origins of how liquid metal inclusions deform and assemble in soft solids. This is achieved through a combination of controlled processing strategies such as film embossing, tentering or stretching, and roll-to-roll assembly with in-situ electrical characterization and synchronized micro- and nano-computed tomography. This approach provides the processing-structure-property relationships needed for the advanced manufacturing of soft composites through mechanically induced assembly of liquid microstructures in elastic films. The project aims to determine the fundamental liquid metal inclusion deformation mechanisms and ensuing microstructures as a function of inclusion size, shape, and volume loading. Soft functional composites with programmable properties will be created through reconfigurable microstructures by controlling droplet inclusion shape and connectivity during processing. This project will provide insights on manufacturing and assembly of liquid structures within soft elastic films, introduce new directions to control material properties through reconfigurable liquid microstructures, and enable the design and manufacturing of materials for soft electronics and robots.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.