Advanced Algorithms for Colloids with Induced Many-Body Interactions

非技术总结该奖项支持计算和理论研究，重点是开发新的方法来使用计算机模拟来理解胶体颗粒的自组装，尺寸在1到1000纳米范围内的物体，悬浮在另一种介质中。它们可以作为构建块来创建可以通过外部电场和磁场重新配置和调整的新材料，这已成为当前材料科学和工程的重要焦点。这种材料有着广泛的应用，但人们对组成材料的各个构件如何响应随时间变化的场知之甚少，例如由交流电供电的电磁体产生的场。PI和他的研究团队正在开发新的计算方法，使其能够以前所未有的准确性预测和理解这些特性，为设计响应性材料开辟了道路。同样的算法也可以用于理解和改进微流体装置，其中微量的流体被操纵，例如用于分析目的。该项目开发的计算方法将被集成到材料和其他研究社区广泛使用的计算机模拟软件包中。PI将继续维护一个Wiki，提供他的小组开发的计算工具，该工具已成为更广泛的计算研究社区的资源。技术总结该奖项支持计算和理论研究，重点是加速算法的开发和应用，这些算法考虑了由电和磁极化引起的诱导多体相互作用。这些方法将用于探索和理解各向异性胶体在外场中的新动力学行为，并设计用于目标自组装的构建模块。悬浮液中胶体颗粒的动力学和自组装受到广泛关注，因为它们允许创建具有新结构的材料。直到最近才有算法，使人们有可能模拟这些现象，同时考虑到充分解决表面极化。PI现在将利用这种方法来探索和理解各向异性胶体在外场中的行为，在外场中，双电层被扭曲，引起诱导的相互作用甚至推进，导致集体动力学。此外，该算法将扩展到体极化率，一个现象，直到现在几乎没有被计算探索，并混合方法，将加速模拟的重要类别的介电模型系统的两个数量级相比，目前可能的。近年来，人们越来越多地关注自然界中普遍存在的介电失配的作用，但由于其计算的复杂性，传统上被忽视。在美国国家科学基金会的支持下，PI开发了一个研究项目，提供了一种能够处理移动的电介质物体的实用边界元方法。目前的项目应用这种方法来了解模型系统中的活性物质的推进机制和微流体装置中的电渗流行为。此外，一个等效的算法的发展，为体可重构材料的行为，已经几乎没有探索适当的计算technology.This研究是及时的，因为控制胶体相互作用是一个焦点，在可重构材料的发展将使研究。计算方法和资源现在能够为实验提供直接指导。本研究的进展将大大扩展现有的能力，并阐明动态集体现象以及诱导相互作用驱动的自组装。本项目开发的计算方法将被集成到材料和其他研究社区广泛使用的计算机模拟软件包中。PI将继续维护一个Wiki，该Wiki提供他的团队开发的计算工具，该工具已成为更广泛的计算研究社区的资源。

NONTECHNICAL SUMMARYThis award supports computational and theoretical research with a focus on developing new ways to use computer simulation to understand self-assembly of colloidal particles, objects with sizes in the range 1 to 1000 nanometers, suspended in another medium. They can be used as building blocks to create new materials that can be reconfigured and tuned by means of external electric and magnetic fields, which has become an important focal point of current materials science and engineering. Such materials find a wide range of applications, but it is poorly understood how the individual building blocks making up the material respond to fields that vary over time, such as those generated by electromagnets powered by alternating currents. The PI and his research team are developing novel computational methods that make it possible to predict and understand such properties with unprecedented accuracy, opening the way to designing responsive materials. The same algorithms also can be employed to understand and improve microfluidic devices, in which minute amounts of fluids are manipulated, for example for analytic purposes.Computational methods developed by this project will be integrated into computer simulation packages widely used by the materials and other research communities. The PI will continue to maintain a Wiki that provides computational tools developed in his group which has become a resource to the broader computational research community.TECHNICAL SUMMARYThis award supports computational and theoretical research focused on the development and application of accelerated algorithms that account for induced many-body interactions that arise from electric and magnetic polarizability. These methods will be used to explore and understand new dynamical behavior of anisotropic colloids in external fields, and to design building blocks for targeted self-assembly. The dynamics and self-assembly of colloidal particles in suspension are of widespread interest, as they allow the creation of materials with novel structures. Only recently have algorithms become available that make it possible to simulate these phenomena while taking into account fully resolved surface polarization. The PI will now exploit this approach to explore and understand the behavior of anisotropic colloids in external fields, where the electric double layer is distorted, giving rise to induced interactions or even propulsion that results in collective dynamics. Moreover, the algorithms will be extended to bulk polarizability, a phenomenon that until now has barely been explored computationally, and to a hybrid method that will accelerate the simulation of important classes of dielectric model systems by two orders of magnitude compared to what is currently possible.Computer simulations of soft materials now routinely take into account long-range electrostatic interactions. In recent years increasing attention has been devoted to the role of dielectric mismatch ubiquitous in nature but traditionally ignored owing to its computational complexity. With prior NSF support, the PI has developed a research program that has delivered a practically usable boundary-element method capable of dealing with mobile dielectric objects. The current project applies this method to understand the propulsion mechanism in model systems of active matter and the behavior of electro-osmotic flow in microfluidic devices. Moreover, the development of an equivalent algorithm for bulk dielectrics will enable the study of materials behavior that has been virtually unexplored for want of appropriate computational techniques.This research is timely because control over colloidal interactions is a focal point in the development of reconfigurable materials. Computational methods and resources are now able to provide direct guidance to experiments. The advances proposed here will significantly extend existing capabilities and elucidate dynamic collective phenomena as well as self-assembly driven by induced interactions.Computational methods developed by this project will be integrated into computer simulation packages widely used by the materials and other research communities. The PI will continue to maintain a Wiki that provides computational tools developed in his group which has become a resource to the broader computational research community.