Collaborative Research: Self-regulated non-equilibrium assembly of chiral colloidal clusters via electrokinetic interactions

合作研究：通过动电相互作用实现手性胶体簇的自我调节非平衡组装

• 批准号: 2314339
• 负责人: Ning Wu
• 金额: $ 33.82万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2314339&HistoricalAwards=false
• 关键词: Collaborative; Research; Self; regulated; non

Non-technical abstract Autonomous motion and transport of microscopic objects are essential for maintaining the bioactivities of all living species. Although natural systems have evolved to possess extremely delicate biochemical motors, the development of synthetic motors lags way behind in complexity and efficiency. This research aims to provide the fundamental knowledge necessary for developing new types of synthetic microrobots driven by non-invasive alternating-current electric fields. In particular, the research team investigates the interplay between two types of electric-field-induced solvent flow surrounding microscopic particles. Precise control of such kind of particle interactions provides a new mechanism for cargo capture, transport, and delivery by the colloidal micromotors in a lab-on-a-chip device. Moreover, the organized structures formed by those micromotors are excellent building blocks for making functional materials that exhibit exotic optical properties for applications in superlenses, cloaking devices, and molecular sensing. In addition, this award also plans to develop hands-on learning modules to engage underrepresented groups in science and engineering. Technical abstract This project aims to answer a fundamental question in colloidal physics: what is the nature of the electrokinetic flow around a charged dielectric particle near an electrode when subjected to a perpendicularly applied alternating-current electric field? A series of recent experiments strongly suggest that the classical theories on electrohydrodynamic flow and induced-charge electroosmosis flow are insufficient to capture the propulsion and non-equilibrium assembly of charged dielectric particles because it only considers the electroosmotic flow originating from the electrode. Instead, this project investigates the impact of the concentration polarization of the electric double layer around the charged particle on a new type of electrokinetic flow (the concentration-polarization-induced electroosmosis) via complementary experimental and theoretical studies. In addition, the hydrodynamic interactions originating from multiple types of electrokinetic flow are exploited to achieve the self-regulated out-of-equilibrium assembly of multiple colloids into uniform clusters with complex symmetries. Finally, perturbation theory and Brownian dynamics simulations are used to investigate the role of hydrodynamic interactions in the assembly.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.

非技术摘要 微观物体的自主运动和运输对于维持所有生物物种的生物活性至关重要。尽管自然系统已经进化到拥有极其精密的生化马达，但合成马达的发展在复杂性和效率方面远远落后。这项研究旨在为开发由非侵入性交流电场驱动的新型合成微型机器人提供必要的基础知识。研究小组特别研究了微观颗粒周围两种电场引起的溶剂流之间的相互作用。对这种粒子相互作用的精确控制为芯片实验室设备中的胶体微电机捕获、运输和递送货物提供了一种新机制。此外，这些微电机形成的有序结构是制造功能材料的极好构建模块，这些材料在超级透镜、隐形装置和分子传感等应用中表现出奇异的光学特性。此外，该奖项还计划开发实践学习模块，以吸引科学和工程领域代表性不足的群体。技术摘要 该项目旨在回答胶体物理学中的一个基本问题：当受到垂直施加的交流电场时，电极附近带电介电粒子周围的动电流的性质是什么？最近的一系列实验强烈表明，电流体动力流和感应电荷电渗流的经典理论不足以捕获带电介电粒子的推进和非平衡组装，因为它只考虑源自电极的电渗流。相反，该项目通过互补的实验和理论研究，研究带电粒子周围双电层的浓差极化对新型动电流（浓差极化引起的电渗）的影响。此外，利用多种类型动电流产生的流体动力相互作用，实现多种胶体的自调节非平衡组装成具有复杂对称性的均匀簇。最后，微扰理论和布朗动力学模拟用于研究流体动力相互作用在装配中的作用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。