CAREER: Experimental and Theoretical Studies of Mechanics Interacting with Electric/Optical Fields in Liquid Crystal Elastomers

这个教师早期职业发展（CAREER）项目将研究液晶弹性体中的耦合现象，液晶分子和聚合物网络的组合。液晶弹性体具有许多特殊的性质，这些性质导致了从人造肌肉到可拉伸光学器件的各种应用。由于液晶弹性体的分子结构复杂，在液晶弹性体中观察到的许多现象仍然是难以捉摸的，并且液晶弹性体的独特性能还没有被充分探索。这项研究将开发一种创新和强大的技术，以制造具有所需性能的液晶弹性体。PI还将制定液晶弹性体的力学理论，这些弹性体具有可能由各种外部刺激触发的大变形。该项目的成果将促进液晶弹性体的进一步开发，用于广泛的应用，例如用于软机器人的响应元件，用于能量收集/转换系统的活性材料以及用于各种致动器或传感器的软材料。此外，通过课程开发、小型夏令营和高中生拓展等综合教育和拓展计划，扩大项目的影响。本多学科项目的研究目标是利用理论、计算和实验相结合的方法，研究液晶弹性体中的多场耦合现象。我们将开发一种应变工程技术，将预先设计的不均匀应变场施加到轻度交联的液晶弹性体膜上，在其第二步交联反应期间，从而获得材料中的图案化分子取向。结合实验和理论研究，我们将进一步探索液晶弹性体中力学和电/光场之间的相互作用，目标是在材料中实现多种电压或光致变形模式。因此，该研究项目将导致更好地理解液晶弹性体的行为，为具有相似分子结构的生物材料的动态行为提供机理见解，并促进这种特殊材料的新的工程应用。

This Faculty Early Career Development (CAREER) project will investigate coupling phenomena in liquid crystal elastomers, a combination of liquid crystal molecules and polymer networks. Liquid crystal elastomers have many special properties which have led to diverse applications ranging from artificial muscles to stretchable optical devices. Because of the complex molecular structure, many phenomena observed in liquid crystal elastomers are still elusive and the unique properties of liquid crystal elastomers have not been fully explored. This research will develop an innovative and robust technique to fabricate liquid crystal elastomers with desired properties. The PI will also formulate a mechanics theory of liquid crystal elastomers with large deformations that may be triggered by various external stimuli. The results from the project will promote further development of liquid crystal elastomers for a wide range of applications, such as responsive elements used in soft robotics, active materials used in energy harvesting/conversion systems and soft materials used in various actuators or sensors. Moreover, the impact of the project will be broadened via the integrated education and outreach programs including course development, a mini summer camp and outreach to high school students.The research objective of this multidisciplinary project is to investigate multi-field coupling phenomena in liquid crystal elastomers, using a using a combined theoretical, computational, and experimental approach. We will develop a strain-engineering technique to apply predesigned inhomogeneous strain fields onto a lightly-crosslinked liquid crystal elastomer film during its second-step crosslinking reaction so as to obtain patterned molecular orientations in the material. Combining experiments and theoretical studies, we will further explore the interplay between mechanics and electrical/optical field in liquid crystal elastomers with the target of realizing diverse voltage or light-induced deformation modes in the material. As a result, this research project will result in a better understanding of the behaviors of liquid crystal elastomers, provide mechanistic insights into the dynamic behaviors of biological materials with similar molecular structures and promote new engineering applications of the special material.