Energy Landscape Approaches to Understanding Soft Glassy Materials

理解软玻璃材料的能源景观方法

• 批准号: 1609525
• 负责人: John Crocker
• 金额: $ 36万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-12-15 至 2021-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1609525&HistoricalAwards=false
• 关键词: Energy; Landscape; Approaches; Understanding; Soft

NONTECHNICAL ABSTRACTThis award supports computer simulation and associated education aimed to help understand the mechanical properties of a class of materials that are viscoelastic, being neither entirely solid nor liquid, and which include soap foams, toothpaste, mayonnaise and living cells. Remarkably, these seemingly very different materials respond very similarly to being pulled or squeezed, and have largely defied deep understanding. This project builds upon a recent breakthrough that stems from thinking of the system as analogous to a particle rolling downhill on an abstract energy landscape. That is, the seemingly complicated motion of the individual bubbles in a foam, when projected into this abstract space, resembles the twists and turns of a river canyon. The PIs will seek to better understand the shape of the landscape that causes the 'river' to twist and turn as it does, to make new versions of the model that give rise to 'rivers' having different shapes and to add real-world detail to the model. Similar 'landscape' approaches have also been found to be useful in machine learning algorithms with many applications, suggesting that the algorithms we develop and our findings may find useful application outside the field of Materials Research. This project will train both graduate and undergraduate students in this important state of the art research area.TECHNICAL ABSTRACT This award supports theoretical and simulation research and education to understand soft glassy materials, a broad class of materials including foams, emulsions, pastes, slurries and even living cells, that share a common set of unusual viscoelastic properties whose physical origins remain deeply mysterious. It will build upon recent studies using a foam model that show that the unusual mechanics of soft glassy materials - power-law rheology, super-diffusive particle motion and avalanches - are due to fractal properties of the system?s path in configuration space. Specifically, it will extend the model to capture the effects of viscous damping and applied shear, produce models having configuration paths with different fractal dimensions as well as probe the fractal geometry of the energy landscape itself. The net result is the development of a suite of tools for the actuation of non-equilibrium systems to probe and understand the geometry of energy landscapes and its relation to material properties. More broadly, it appears that the behavior of many complex adaptive systems, including the cells in our bodies, may be determined by the minimization of some very complex energy or fitness landscape embedded in a high-dimensional space, whose in-depth study is only now becoming practical due to advances in computation. This interdisciplinary project will provide ample opportunity for graduate and undergraduate student training in the development of state of the art tools for studying such high-dimensional energy and fitness landscapes. The tools developed in this proposal will be disseminated openly, and we anticipate them finding utility outside of material science.

非技术摘要该奖项支持计算机模拟和相关教育，旨在帮助理解一类粘弹性材料的机械性能，这些材料既不完全是固体也不完全是液体，包括肥皂泡沫，牙膏，蛋黄酱和活细胞。 值得注意的是，这些看似非常不同的材料对拉动或挤压的反应非常相似，并且在很大程度上无法深入理解。这个项目建立在最近的一项突破之上，该突破源于将该系统视为类似于在抽象能量景观上向下滚动的粒子。 也就是说，泡沫中单个气泡的看似复杂的运动，当投射到这个抽象的空间时，就像河流峡谷的曲折。 PI将寻求更好地理解导致“河流”扭曲和转弯的景观形状，制作新版本的模型，使“河流”具有不同的形状，并为模型添加真实世界的细节。 类似的“景观”方法也被发现在具有许多应用的机器学习算法中是有用的，这表明我们开发的算法和我们的发现可能在材料研究领域之外找到有用的应用。 该项目将培养研究生和本科生在这一重要的最先进的研究领域。技术摘要该奖项支持理论和模拟研究和教育，以了解软玻璃材料，一个广泛的材料类别，包括泡沫，乳液，糊状物，浆料，甚至活细胞，共享一套共同的不寻常的粘弹性性质，其物理起源仍然是深深的神秘。 它将建立在最近的研究使用泡沫模型，表明软玻璃材料的不寻常的力学-幂律流变学，超扩散粒子运动和雪崩-是由于系统的分形特性？的路径。 具体而言，它将扩展模型，以捕捉粘性阻尼和施加的剪切的影响，产生具有不同分形维数的配置路径的模型，以及探测能量景观本身的分形几何。 最终结果是开发了一套用于驱动非平衡系统的工具，以探索和理解能量景观的几何形状及其与材料特性的关系。 更广泛地说，许多复杂适应系统的行为，包括我们身体中的细胞，可能是由嵌入在高维空间中的一些非常复杂的能量或适应度景观的最小化决定的，由于计算的进步，对其深入研究现在才变得实用。这个跨学科的项目将为研究生和本科生提供充足的机会，培训他们开发最先进的工具来研究这种高维能量和健身景观。 本提案中开发的工具将公开传播，我们预计它们将在材料科学之外找到用途。