Modeling Actuation and Shape Selection in Soft Materials

该奖项支持理论研究，包括分析和计算，涵盖基础物理到工业应用的一系列问题。研究的重点是柔软的材料，可能在橡胶中发现或自然在生物系统中，如肌肉。这项研究将着眼于某些类型的类橡胶材料如何对电流等外部刺激做出反应。另一个研究课题是生物分子和简单的生物结构如何组装形成更复杂的结构。这项研究将涉及学生和博士后研究助理。主要研究人员将对软质材料的形状演变进行理论分析和计算机模拟研究。首先，他们专注于液晶弹性体的驱动，液晶弹性体会随着温度、外加电场和光学照明的变化而改变形状。这些材料可以弯曲，也可以拉长和收缩，有可能被用作机器人、MEMS和微流体应用的“人造肌肉”。其次，主要研究人员将研究两亲分子的自组装微观结构，如脂质小管和螺旋带，它们在溶液中自发形成复杂的形状。这些结构在微胶囊化和控释方面有应用，也可以作为模板形成金属微结构，用于微波吸收复合材料。这种类型的自组装也可以在生物材料中观察到，如胆汁，无论是体内还是体外。在液晶弹性体和自组装的管和带中，感兴趣的材料表现出不寻常的铁弹性，铁电性和/或挠性电的组合。材料的介观有序和手性/手性对称性破缺也起着重要的作用。材料特性的每一种独特组合都为技术发展创造了新的机会，也为基础理论和材料工程带来了新的挑战。智力优势：该项目的主要目标是(1)在这些材料的基础理论的发展方面取得进展，(2)应用该理论创建连续尺度的有限元模拟工具，以在设备级和长时间尺度上模拟这些材料的动力学。因此，该项目旨在弥合从基础软凝聚态理论到材料工程甚至产品设计的差距。这种新的模拟工具代表了有限元弹性动力学在研究软质材料中介层序演化引起的形状变化方面的新应用。两位主要研究人员在分析计算和计算机模拟方面有着卓有成效的合作记录，并为这项工作带来了互补的专业知识。肯特州立大学液晶研究所是软材料研究的卓越中心，为这项研究提供了理想的场所。更广泛的影响：该项目将涉及一名研究生和博士后的积极参与，以及肯特州立大学化学物理跨学科项目提供的学生的额外参与。两位调查人员在招募和与女性和少数族裔学生合作方面都有出色的记录，并且已经有女性和少数族裔学生在肯特州立大学的小组中工作。调查人员将参与液晶研究所正在进行的社区外展活动，包括在当地K-12学校的演讲和接待来访的学生团体。本文所研究的软质材料具有广泛的技术应用前景。通过液晶研究所完善的工业合作计划，我们计划将开发的仿真工具和技术概念转化为商业用途。

This award supports theoretical research, both analytical and computational, on a range of problems that span fundamental physics to industrial applications. The research focus is on soft materials as might be found in rubbers or naturally in biological systems, e.g., muscles. The research will look at how certain types of rubber-like materials respond to external stimuli such as electric currents. Another topic of research is how biomolecules and simple biological structures assemble to form more complex structures. The research will involve students and postdoctoral research associates.The principal investigators will carry out theoretical analysis and computer simulation studies of two problems related to shape evolution in soft materials. First, they focus on the actuation of liquid crystal elastomers, which change their shape in response to changes in temperature, applied electric fields, and optical illumination. These materials can bend as well as lengthen and contract, and have the potential to be used as "artificial muscles" for robotics, MEMS, and microfluidics applications. Second, the principal investigators will investigate self-assembled microstructures of amphiphilic molecules, such as lipid tubules and helical ribbons, which spontaneously form in complex shapes out of solution. These structures have applications in microencapsulation and controlled release, and can also serve as templates to form metallic microstructures used in microwave-absorbing composite materials. This type of self-assembly is also observed in biological materials, such as bile, both in vivo and in vitro.In both liquid crystal elastomers and in self-assembly of tubules and ribbons, materials of interestexhibit unusual combinations of ferroelasticity, ferroelectricity, and/or flexoelectricity. Mesogenic ordering of the material and chirality/chiral symmetry-breaking also play important roles. Each unique combination of material properties creates new opportunities for technology development and new challenges for both fundamental theory and materials engineering.Intellectual merit: The primary goals of the project are (1) to make progress with thedevelopment of fundamental theory of these materials, and (2) to apply that theory to create acontinuum-scale finite element simulation tool to model the dynamics of these materials at thedevice level and on long time scales. This project is thus intended to bridge the gap fromfundamental soft condensed matter theory to materials engineering and even product design. Thenew simulation tool represents a novel application of finite element elastodynamics to study shape changes caused by evolving mesogenic order in soft materials. The principal investigators have a strong record of fruitful collaboration and bring complementary expertise in analytical calculations and computer simulation to the work. Kent State University's Liquid Crystal Institute is a center of excellence in the study of soft materials and provides an ideal location for this research.Broader impacts: The project will involve the active participation of a graduate student and apostdoctoral fellow, with additional participation of students provided by the Chemical Physics Interdisciplinary Program at Kent State University. Both investigators have an exceptional track record in recruiting and working with female and minority students, and already have female and minority students working in their group at Kent State University. The investigators will participate in the Liquid Crystal Institute's ongoing community outreach activities, including presentations at local K-12 schools and hosting visiting student groups. The soft materials studied here are promising for a wide range of technological applications mentioned above. Through the Liquid Crystal Institute's well-established Industrial Partnership Program, we plan to transition the developed simulation tools and technological concepts for commercial use.