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Topological Guidance of Self-Propelled Janus Locomotors Along Solid Boundaries

沿实体边界自驱动 Janus 运动机的拓扑引导

基本信息

批准号：
1805554
负责人：
Charles Maldarelli
金额：
$ 38万
依托单位：
CUNY City College
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2022-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1805554&HistoricalAwards=false
关键词：
Topological Guidance Self Propelled Janus

项目摘要

This research studies self-propelling microbots. These are ultra-miniaturized locomoting vehicles which are microns in size - the dimensions of a red blood cell or a grain of pollen. Microbots travel independently in a liquid environment such as water by consuming fuel present in the environment, and converting the chemical energy of the fuel into mechanical motion. Due to their small size and their ability to motor around by themselves as active matter, self-propelled microbots are at the center of innovative applications on the technological horizon. Their medical applications are the most promising: Microbots are envisioned to be able to dock with sperm and assist their movement towards an egg for fertilization, navigate blood vessels to unclog arteries, and ferry drugs to targeted sites in the human body such as tumors or diseased organs. The ability to steer microbots along prescribed pathways is essential. While on board guidance systems which respond to external instructions can be used for navigation, this research focuses on passive guidance in which the microbot responds to cues in its environment to guide itself. In particular, this research studies how a microbot can passively follow along a planar wall at a fixed height above the wall, or steer around a post. The passive guidance originates from how the boundary changes the conversion of the chemical energy into mechanical motion, and how the microbot interacts fluid dynamically with the boundary. Educationally, the grant will fund two graduate students, one on theory and one on experiments; their synergistic effort will broaden each of their academic horizons. An outreach effort to two local high schools, one in New York and one in New Jersey, is in place, and this research will be integrated into the research curriculum experience of these high schools.This research studies a model locomotor consisting of a spherical particle in which one face of the particle is coated with a platinum catalyst to form a two-faced Janus particle. The platinum reacts with hydrogen peroxide, as a fuel, in the environment to produce oxygen and water. The reaction of the peroxide on the active face creates gradients in the ionic disassociation products of the peroxide across the particle which in turn generates electrokinetic propulsive forces. While this mechanism explains the locomotion of these Janus engines in free space, this study examines the electrokinetic propulsion in the vicinity of boundaries and aims to determine theoretically and experimentally if boundary guidance is possible with electrokinetic propulsion. Two examples will be investigated, the ability of Janus locomotors to be guided along a wall, and their ability to circumnavigate a post attached (perpendicular) to a wall. Theoretically, the electrohydrodynamic equations will be solved to obtain deterministic trajectories, and Brownian dynamics simulations will be undertaken to understand the stability of guided states to thermal fluctuations. Experiments will also be undertaken on guidance on these two surface topologies.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.

这项研究研究了自我推进的微型机器人。这些都是超小型的交通工具，其尺寸为微米-红细胞或花粉粒的尺寸。微机器人通过消耗环境中存在的燃料并将燃料的化学能转化为机械运动来在液体环境（例如水）中独立行进。由于它们的小尺寸和它们作为活性物质自行运动的能力，自推进微型机器人是技术领域创新应用的中心。它们的医疗应用是最有前途的：微型机器人被设想能够与精子对接并帮助它们向卵子移动以受精，导航血管以疏通动脉，并将药物运送到人体的目标部位，如肿瘤或患病器官。控制微型机器人沿着沿着规定的路径前进的能力是至关重要的。虽然响应外部指令的车载导航系统可以用于导航，但本研究的重点是被动导航，其中微型机器人响应其环境中的提示来引导自己。特别是，这项研究研究如何微机器人可以被动地遵循沿着一个平面的墙壁在一个固定的高度以上的墙壁，或转向周围的职位。被动引导源于边界如何改变化学能向机械运动的转化，以及微型机器人如何与边界动态地进行流体相互作用。在教育方面，这笔赠款将资助两名研究生，一名研究理论，一名研究实验;他们的协同努力将拓宽他们各自的学术视野。一个外展工作，以两个当地的高中，一个在纽约和一个在新泽西，是在地方，这项研究将被纳入这些高中的研究课程的经验。本研究研究的模型运动组成的球形粒子，其中一个粒子的一面涂有铂催化剂，形成一个双面的Janus粒子。铂与过氧化氢反应，作为燃料，在环境中产生氧气和水。过氧化物在活性面上的反应在过氧化物的离子解离产物中产生穿过颗粒的梯度，这进而产生动电推进力。虽然这种机制解释了这些Janus发动机在自由空间中的运动，本研究探讨了在边界附近的电动推进，并旨在从理论和实验上确定，如果边界的指导是可能的电动推进。我们将研究两个例子，一个是雅努斯运动体被引导沿着墙壁的能力，另一个是它们绕着一个附着（垂直）在墙壁上的柱子的能力。从理论上讲，将解决电流体动力学方程，以获得确定性的轨迹，布朗动力学模拟将进行了解热波动的引导状态的稳定性。该奖项反映了NSF的法定使命，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。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Continuum and Molecular Dynamics Studies of the Hydrodynamics of Colloids Straddling a Fluid Interface

跨越流体界面的胶体流体动力学的连续体和分子动力学研究

DOI：
10.1146/annurev-fluid-032621-043917
发表时间：
2022
期刊：
Annual Review of Fluid Mechanics
影响因子：
27.7
作者：
Maldarelli, Charles;Donovan, Nicole T.;Ganesh, Subramaniam Chembai;Das, Subhabrata;Koplik, Joel
通讯作者：
Koplik, Joel

Pairwise hydrodynamic interactions of spherical colloids at a gas-liquid interface