CAREER: Electro-Mechanical Behaviors of Soft Conductive Composites Embedded with Liquid Metal Fiber Networks

该学院早期职业发展（CAREER）资助将支持液态金属纤维网络复合材料机电行为的基础研究。这种新的软导电复合材料的范例是超拉伸，高导电性，重量轻，成本低，由于其独特的微结构架构。 因此，这种液态金属纤维网络复合材料将极大地有利于在美国的柔性电子工业，并将有其他重要的技术应用，如软传感器和执行器，软机器人，能量采集器等。这项研究将首先提供表征和更好地了解大变形下的液态金属纤维网络复合材料的微观结构演变和机电行为。这些新知识对于液态金属纤维网络复合材料的微观结构设计、材料加工和工程分析具有重要意义。研究和教育的整合将侧重于学生培训和行业参与，以教育更多的工程师从事液态金属材料的研究和设计。教育和推广计划将为K-12和本科生提供互动和动手活动，以发明自己的软电子产品。其他关键的教育目标包括开发新课程，举办在线研讨会，以及维护液态金属材料的网页。 研究的具体目标是揭示网络几何形状对液态金属纤维网络复合材料机电行为的影响。将采用综合实验-理论-计算的方法来揭示极大变形下的网络几何演化，表征跨纤维和网络尺度的机电行为，并建立考虑材料各向异性和非亲和性的多物理场本构建模框架。微观结构的架构，纤维和结形态，和机械变形的网络几何形状的演变和液态金属纤维网络复合材料的机电行为的影响将被阐明和建模。所研究的本构模型和计算微观力学模型将通过各种实验技术进行验证，包括微纳米计算机断层扫描成像，原位网络几何跟踪和同步机电测试。液态金属纤维网络复合材料与不同的微结构体系结构将制造和特点使用技术独特的PI开发。所研究的理论模型、仿真工具和实验方法将适用于广泛的软导电复合材料。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值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 will support fundamental research on the electro-mechanical behaviors of liquid metal fiber network composites. This new paradigm of soft conductive composites is super-stretchable, highly conductive, lightweight, and low cost due to its unique microstructural architectures. Therefore, such liquid metal fiber network composites will greatly benefit the flexible electronics industry in the USA and will have other important technological applications such as soft sensors and actuators, soft robotics, energy harvesters, etc. This research will first provide characterization and better understanding of the microstructural evolution and electro-mechanical behaviors of liquid metal fiber network composites under large deformation. Such new knowledge is critical to the microstructural design, material processing, and engineering analysis of liquid metal fiber network composites for future engineering applications. The integration of research and education will focus on student training and industry engagement to educate more engineers doing research and design for liquid metal materials. The education and outreach program will offer interactive and hands-on activities for K-12 and undergraduate students to invent their own soft electronics. Other key education objectives involve developing a new curriculum, hosting online webinars, and maintaining a webpage for liquid metal materials. The specific goal of the research is to discover the influence of network geometry on electro-mechanical behaviors of liquid metal fiber network composites. An integrated experimental-theoretical-computational approach will be employed to uncover the network geometry evolution under extremely large deformation, characterize electro-mechanical behaviors across fiber and network scales, and establish a multiphysics constitutive modeling framework considering material anisotropy and non-affinity. The effects of microstructural architectures, fiber and junction morphologies, and mechanical deformation on the network geometry evolution and electro-mechanical behaviors of liquid metal fiber network composites will be elucidated and modeled. The researched constitutive models and computational micromechanics models will be verified by various experimental techniques involving micro- and nano-computed tomography imaging, in-situ network geometry tracking, and synchronized electro-mechanical testing. Liquid metal fiber network composites with different microstructural architectures will be fabricated and characterized using techniques uniquely developed by the PI. The researched theoretical models, simulation tools, and experimental methodology will be applicable to a broad class of soft conductive composites.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.