NSF-BSF: Modeling and Control of Collective Dynamics for Externally Driven Planar Microswimmers

该基金将资助在各种医疗保健应用中创新使用微型机器人设备的研究，包括非侵入性手术、药物输送、感染和不孕症治疗，从而促进科学进步，促进国家繁荣和健康。这种微型机器人装置的部署需要理解微尺度推进的原理，例如微生物在各种流体环境中的游动，以及控制推进的方法的发展。该项目旨在解决目前我们在如何在生物医学相关的真实液体（包括生理盐水、甲基纤维素和合成粘液）中实现单平面机器人微游泳者和此类游泳者群体的控制推进方面的知识空白。在这个项目中进行的理论和实验工作结合了流体力学、小规模制造和控制理论。该项目将受益于美国和以色列研究人员之间独特的国际合作。以微型游泳者为中心的教育活动，以及他们的推进和控制，将被纳入教学和外展，帮助扩大目前代表性不足的群体对STEM的参与。本研究旨在为在牛顿和非牛顿流体环境（包括仿生类组织材料）中进行低雷诺数推进的微游泳机器人的优化设计和控制做出基础贡献。通过研究可使用标准光刻成体制造的平面微结构，以及探索通过几何变化、表面功能化和使用激光激发、化学催化、热梯度和磁场的外部驱动实现的不同步态，研究人员实现了这一结果。该研究将建立一个基于随机微分方程的平面螺旋桨响应环境干扰行为模型，并设计一种反馈控制算法，在跟踪随机运动目标或在随机漂移存在的情况下实现最优路径规划和导航时预测不确定性。这项工作将有助于对复杂流体环境中微游泳者的可操作性和路径规划的实际理解，无论是个体还是群体。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This grant will fund research that enables innovative uses of microrobotic devices in a variety of healthcare applications, including non-invasive surgery, drug delivery, and treatment of infection and infertility, thereby promoting the progress of science and advancing the national prosperity and health. Deployment of such microrobotic devices requires an understanding of principles of microscale propulsion, for example swimming of microorganisms in various fluidic environments, and the development of methodologies to control propulsion. This project aims to address a current gap in our knowledge of how to achieve controlled propulsion of single planar robotic microswimmers and groups of such swimmers in real fluids of biomedical relevance, including saline, methylcellulose, and synthetic mucus. The theoretical and experimental work conducted in this project brings together fluid mechanics, small-scale fabrication, and control theory. The project will benefit from a unique international collaboration between researchers in the US and Israel. Educational activities centered on microswimmers, as well as their propulsion and control, will be integrated in instruction and outreach, helping to broaden participation in STEM from currently underrepresented groups.This research aims to make fundamental contributions to the optimal design and control of robotic microswimmers for low-Reynolds-number propulsion in both Newtonian and non-Newtonian fluidic environments, including biomimetic tissue-like materials. It achieves this outcome by investigating planar microstructures that can be fabricated in bulk using standard photolithography, and exploring different gaits realized through variations in geometry, surface functionalization, and external actuation using laser excitation, chemical catalysis, thermal gradients, and magnetic fields. The research will result in the development of a stochastic differential-equation-based model of planar propeller behavior in response to environmental disturbances, as well as the design of a feedback control algorithm that anticipates uncertainty while tracking stochastic moving targets or realizing optimal path-planning and navigation in the presence of stochastic drifts. The work will contribute to a practical understanding of maneuverability and path planning of microswimmers in complex fluidic environments, both individually and in swarms.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.