Nanomechanics of Mechanically Active Polymers

机械活性聚合物的纳米力学[j]: William P. King1, Co-PI: Ken Gall1,21George W. Woodruff机械工程学院，2佐治亚理工学院材料科学与工程学院，Atlanta， GA 30332纳米尺度有机致动器在各种生物系统中的关键功能。尽管许多研究已经在相对较大的尺度上描述了合成有机驱动，但迫切需要减少现有驱动器的尺寸，以便与某些生物系统直接相互作用，并促进与新兴纳米系统的集成。小尺度的活性聚合物变形将在生物学、医学和工程中得到应用。本研究的目的是研究先进活性高分子材料的纳米力学。具体目标是：(1)利用原子力显微镜（AFM）和压印光刻实验了解形状记忆聚合物和液晶弹性体中纳米尺度应变存储和恢复的基本原理。(2)利用分子动力学模型解决了形状记忆聚合物和液晶弹性体中纳米尺度应变存储和恢复的物理现象。(3)以研究计划为载体，为各级学生创造一个独特而令人兴奋的学习纳米科学和纳米技术的教育机会。拟议的研究结合了实验和理论方法以及AFM，活性聚合物和原子建模方面的专业知识。AFM印模实验将用于研究变形尺寸、温度和聚合物结构对形状记忆聚合物应变存储和恢复以及液晶弹性体光激活驱动的影响。多尺度分子动力学模拟将用于确定材料的操作变形机制，并帮助解释AFM实验的结果。实验和模拟将紧密耦合，因此实验结果有助于推动建模研究，反之亦然。这项研究由两个技术试验台推动；纳米包装递送系统和活性生物支架。这项研究的智力价值在于首次在纳米尺度上对机械活性聚合物进行测量和建模。这项研究通过对活性聚合物的理解取得了根本性的进步，从而产生了广泛的影响，这将有助于所有长度尺度的聚合物科学家和工程师。这项研究是合理设计具有纳米级能量存储、处理和传输能力的工程仿生系统的必要的第一步。这项研究强调小学和高中学生、本科生、研究生的参与、教育和培训，他们都将从接触纳米科学和纳米技术研究中受益。

Nanomechanics of Mechanically Active PolymersPI: William P. King1, Co-PI: Ken Gall1,21George W. Woodruff School of Mechanical Engineering, 2School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332Nanometer scale organic actuators perform critical functions in various biological systems. Although much research has characterized synthetic organic actuation at relatively large scales, it is highly desirable to reduce the size of present actuators to allow direct interaction with certain biological systems and facilitate integration with emerging nanosystems. Active polymer deformation at small scales would have applications in biology, medicine, and engineering. The goal of the proposed research is to investigate nanomechanics in advanced active polymer materials. The specific objectives are to: (1) Understand the fundamentals of nanometer-scale strain storage and recovery in shape memory polymers and liquid crystal elastomers using atomic force microscopy (AFM) and imprint lithography experiments. (2) Resolve the physical phenomena in the storage and recovery of nanometer-scale strains in shape memory polymers and liquid crystal elastomers using molecular dynamics modeling. (3) Use the research program as a vehicle to create a unique and exciting educational opportunity for students at all levels to learn about nanoscience and nanotechnology.The proposed research combines experimental and theoretical approaches and expertise in AFM, active polymers, and atomistic modeling. AFM impression experiments will be used to study the effects of deformation size-scale, temperature, and polymer structure on strain storage and recovery in shape memory polymers and light activated actuation in liquid crystal elastomers. Multi-scale molecular dynamics simulations will be used to ascertain operant deformation mechanisms in the materials and to help interpret results of AFM experiments. The experiments and simulations will be tightly coupled so experimental findings help to drive modeling studies and vice-versa. The research is driven by two technology test-beds; a nanopackage delivery system and an active biological scaffold. The intellectual merit of the research lies in the first-ever measurements and modeling of mechanically active polymers at nanometer scales. The research achieves broad impact through a fundamental advancement in the understanding of active polymers that will aid polymer scientists and engineers at all length scales. The research is the necessary first step in the rational design of engineered biomimetic systems capable of nanometer-scale energy storage, processing, and delivery. The research emphasizes the participation, education, and training of elementary school and high school students, undergraduates, graduate students, who will all benefit from exposure to nanoscience and nanotechnology research.