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.

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。虽然自然系统已经进化到拥有极其精细的生化马达，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。特别是，研究小组研究了两种类型的电场诱导的溶剂流围绕微观颗粒之间的相互作用。这种粒子相互作用的精确控制提供了一种新的机制，货物捕获，运输和交付的胶体微电机在一个芯片上的实验室设备。此外，由这些微马达形成的有组织的结构是用于制造功能材料的极好的构建块，这些功能材料表现出用于超透镜、隐形装置和分子传感的奇异光学特性。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。本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，电极附近的带电电介质颗粒周围的电动流动的性质是什么？最近的一系列实验表明，经典的电流体动力学理论和诱导电荷电渗理论只考虑了电极产生的电渗流，不足以描述带电介质粒子的推进和非平衡组装。相反，本项目通过补充实验和理论研究，研究带电粒子周围双电层的浓差极化对新型电动流（浓差极化诱导电渗）的影响。此外，源自多种类型的电动流动的流体动力学相互作用被利用来实现多个胶体的自调节的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被用来研究流体动力学相互作用在assembly.This奖项反映了NSF的法定使命的作用，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。