Collaborative Research: Multiscale engineering of active stress in biomaterials

非技术摘要：生物系统表现出显着的行为，包括愈合，繁殖和自我运动的能力。传统的合成材料不显示这样的特性，因为它们是由无生命的分子组成的。相比之下，生物系统由活跃的能量转换分子组成，这些分子不断地相互推拉，产生积极的压力。这些活跃的压力使生物系统成为活跃物质的例子，并最终导致了许多不寻常的行为。创造人工活性物质为构建具有逼真功能的材料开辟了一条新途径。然而，实现这种可能性的一个重大障碍是缺乏对主动应力如何产生的理解：给定特定的元素构建块，目前没有工具来测量或理论上预测主动应力的大小，类型甚至符号。该项目将阐明主动应力产生的基本原理，使用实验，模拟和理论的协同组合。这项工作将导致创建新的实验工具来测量活性应力，创建活性材料的新合成程序，以及研究活性物质的新多尺度建模技术。一个综合的推广计划将带来兴奋的活性物质的K-12教育，本科生和研究生相结合的互动演示，先进的跨学科培训，和密集的暑期courses.Technical摘要：该研究的重点是研究组装的微管和驱动蛋白-14分子马达。这项工作解决了三个基本的挑战，在理解主动应力产生的活性材料。首先是开发工具，使用光学镊子，流体流动测量，微流体和3D打印，结合理论和模拟来测量不同长度尺度的主动应力。第二，将创建一个新的系统，其中主动应力的产生将被调制直接附着驱动蛋白-14到微管在预定的模式。理论和模拟将用于指导创建哪些图案，相反，测量这些设计材料中产生的主动应力将提供对理论和模拟的严格测试。第三，将开发和测试多尺度建模框架。随后将通过分析计算和模拟相结合将这些相互关联。由此产生的模型将通过不断的实验反馈来制作。总之，这项工作将建立新的范式来研究，理解，这项DMR拨款支持研究，以了解微管和驱动蛋白-14分子马达的组装，资金来自凝聚态物理学（CMP）和生物材料（BMAT）该奖项反映了NSF的法定使命，通过使用基金会的知识价值和更广泛的影响审查标准进行评估，认为值得支持。

Nontechnical Abstract:Biological systems exhibit remarkable behaviors, including the ability to heal, reproduce, and be self-motile. Conventional synthetic materials do not display such properties because they are composed of inanimate molecules. In contrast, biological systems consist of active, energy transducing molecules which continuously push and pull on each other, producing active stresses. These active stresses make biological systems examples of active matter, and are ultimately are responsible for many of their unusual behaviors. Creating artificial active matter opens up a new route towards constructing materials with lifelike functionalities. However, a significant obstacle to realizing this possibility is an absence of understanding of how active stresses are produced: given specific elemental building blocks, there are not currently tools to either measure or theoretically predict the magnitude, type, or even the sign of the active stresses. The project will elucidate the foundational principles of active stress generation using a synergistic combination of experiments, simulations, and theory. The work will result in the creation of new experimental tools for measuring active stresses, new synthesis procedures for creating active materials, and new multi-scale modeling techniques for studying active matter. An integrated outreach program will bring the excitement of active matter to K-12 education, undergraduates, and graduates by combining interactive demonstrations, advanced interdisciplinary training, and intensive summer courses.Technical Abstract:The research focuses on studying assemblages of microtubules and kinesin-14 molecular motors. The work addresses three fundamental challenges in understanding active stresses generated by such active materials. First is the development of tools to measure active stresses at different length scales using optical tweezers, fluid flow measurements, microfluidics, and 3D printing, in combination with theory and simulations. Second, a novel system will be created in which active stress generation will be modulated by directly affixing kinesin-14 to microtubules in predetermined patterns. Theory and simulations will be used to guide which patterns to create, and conversely, measuring the resulting active stress generation in these designed materials will provide a stringent test of theory and simulations. Third, a multi-scale modeling framework will be developed and tested. These will be subsequently related to each other through a combination of analytical calculations and simulations. The resulting models will be made with continual feedback from experiments. Taken together, this work will establish new paradigms to study, understand, and engineer active stresses in active materials.This DMR grant supports research to understand the assemblages of microtubules and kinesin-14 molecular motors with funding from the Condensed Matter Physics (CMP) and Biomaterials (BMAT) Programs in the Division of Materials Research of the Mathematical and Physical Sciences Directorate.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.