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

这个学院早期职业发展项目将研究液晶弹性体中的耦合现象，液晶弹性体是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，这导致了从人造肌肉到可伸展光学设备的各种应用。由于液晶弹性体具有复杂的分子结构，许多现象仍不清楚，液晶弹性体的独特性能还没有得到充分的研究。这项研究将开发一种创新和稳健的技术来制造具有所需性能的液晶弹性体。PI还将阐述液晶弹性体的力学理论，这些弹性体可能会在各种外部刺激下发生大变形。该项目的成果将促进液晶弹性体的进一步开发，应用范围广泛，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，以及用于各种执行器或传感器的软材料。此外，该项目的影响将通过综合教育和外展计划扩大，包括课程开发、小型夏令营和对高中生的外展。这个多学科项目的研究目标是使用理论、计算和实验相结合的方法来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，在轻度交联的液晶弹性体膜的第二步交联反应中，将预先设计的不均匀应变场应用于其上，以获得材料中的图案化分子取向。我们将通过实验和理论研究相结合的方法，进一步探索液晶弹性体中力学和电/光场之间的相互作用，以实现材料中不同的电压或光致变形模式。因此，这一研究项目将有助于更好地了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力学行为提供力学上的见解，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.