CAREER: Mechanics of Active Polymers and Morphing Structures: Determine the Role of Molecular Interactions and Stiffness Heterogeneity in Reversible Shape Morphing

职业：活性聚合物和变形结构的力学：确定分子相互作用和刚度异质性在可逆形状变形中的作用

• 批准号: 2144687
• 负责人: Xueju Wang
• 金额: $ 54.68万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144687&HistoricalAwards=false
• 关键词: CAREER; Mechanics; Active; Polymers; Morphing

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).This Faculty Early Career Development (CAREER) grant will support research on fundamental studies of the mechanics of innovative active polymers and morphing structures. Soft morphing polymers that can change their shapes and therefore functionalities upon exposure to external stimuli are important for many applications, including soft robotics, artificial muscles, and tissue repair. Despite advancement in this exciting and ever-growing field, the rational design, manufacturing, and applications of innovative morphing materials and structures have been significantly limited by the lack of fundamental mechanics understanding of novel active polymers like liquid crystal elastomers. This research project will establish the missing complicated correlations across the molecular, material, and structural levels of novel active materials by using liquid crystal elastomers as a model material system. The educational objective of this work is to engage students at different levels and the general public to research frontiers in morphing materials and structures. An overarching program “Morphing Beyond Imagination” will be started, where simple and entertaining demonstrations of morphing flowers, spiders, and octopuses will be provided to elementary students and will be used to help develop curricula for high school students to promote their pursuit of STEM related studies. Research experiences to undergraduate students especially female and low-income students through a summer intern and a McNair scholar program will be provided. The research objective of this project is to uncover the complicated relationships among molecular interactions, heterogeneous material properties, and the shape morphing behavior of structures, and establish an integrated experimental and computational framework for the rational design of morphing materials and structures by using liquid crystal elastomers as an example. To achieve this objective, the specific tasks of this project include: (1) establish the correlations between molecular interactions (crosslinking density, chain alignment, and chain length) and material properties (stiffness and actuation strain in two-way shape changes), (2) build an integrated experimental and computational framework to study the shape morphing of liquid crystal elastomer structures under molecular-material interactions, and (3) investigate shape morphing and reprogramming under complicated spatial mesogen alignment and stiffness heterogeneities. The research outcomes of this work will help understand and optimize the design of novel active polymers and morphing structures with tailored chain alignment, stiffness heterogeneity, and shape morphing properties under complicated loading conditions and external stimuli. In addition, the project will generate broad impacts on a variety of other disciplines, including chemistry, physics, materials science, and biomedical engineering.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.

该奖项的全部或部分资金根据《2021 年美国救援计划法案》（公法 117-2）提供。该教师早期职业发展 (CAREER) 赠款将支持创新活性聚合物和变形结构力学的基础研究。软变形聚合物可以在受到外部刺激时改变其形状并因此改变其功能，这对于许多应用都很重要，包括软机器人、人造肌肉和组织修复。尽管这个令人兴奋且不断发展的领域取得了进步，但由于缺乏对液晶弹性体等新型活性聚合物的基本力学理解，创新变形材料和结构的合理设计、制造和应用受到了严重限制。该研究项目将通过使用液晶弹性体作为模型材料系统，建立新型活性材料在分子、材料和结构层面上缺失的复杂关联。这项工作的教育目标是让不同级别的学生和公众参与变形材料和结构的前沿研究。将启动一项总体计划“超越想象的变形”，向小学生提供简单而有趣的变形花、蜘蛛和章鱼演示，并将用于帮助开发高中生课程，以促进他们对 STEM 相关学习的追求。将通过暑期实习生和麦克奈尔学者计划为本科生尤其是女性和低收入学生提供研究经验。该项目的研究目标是揭示分子相互作用、异质材料特性和结构形状变形行为之间的复杂关系，并以液晶弹性体为例，为变形材料和结构的合理设计建立一个集成的实验和计算框架。为了实现这一目标，该项目的具体任务包括：（1）建立分子相互作用（交联密度、链排列和链长）与材料特性（双向形状变化中的刚度和驱动应变）之间的相关性，（2）建立一个集成的实验和计算框架来研究液晶弹性体结构在分子-材料相互作用下的形状变形，以及（3）研究形状变形和重编程 在复杂的空间介晶排列和刚度异质性下。这项工作的研究成果将有助于理解和优化新型活性聚合物和变形结构的设计，这些聚合物和变形结构在复杂的负载条件和外部刺激下具有定制的链排列、刚度异质性和形状变形特性。此外，该项目还将对化学、物理学、材料科学和生物医学工程等多种其他学科产生广泛影响。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

Morphing of stiffness-heterogeneous liquid crystal elastomers via mechanical training and locally controlled photopolymerization

• DOI: 10.1016/j.matt.2022.08.019
• 发表时间: 2022-09
• 期刊: Matter
• 影响因子: 18.9
• 作者: Yi Li;Gina Parlato;Francis K. Masese;R. Kasi;Teng Zhang;Xueju Wang