CAREER: Harnessing viscous streaming in complex active systems: mini-bots in fluids

人工和生物混合（部分合成，部分生物）微型游泳机器人在血液中导航和输送药物在生物医学中具有巨大的潜力。粘性流是一种振荡体产生稳定、可预测和强大的流体流动的现象，可以用来操纵身体的局部环境。粘性流被提议用于运输、混合和颗粒组装，并且它可能适合用于生物医学应用的微型机器人的运输。一个限制是，虽然流现象在简单物体中被很好地理解，但在复杂几何的情况下却知之甚少。该建议结合建模和实验来解决粘性流与体型之间的知识鸿沟。这些知识将把生物学和机器人技术联系起来，以增强微型机器人的现有能力，并使其成为可能。这项研究将为本地化药物输送、精确操作和制造等变革性应用铺平道路。这符合国家需要通过先进的计算方法提高药品的有效性和制造业的竞争力。本研究在流体力学、模拟、机器人和生物工程等领域具有广泛的教育影响。一套拓展活动和直观的学习模块将被设计，以激发对流体力学和工程的兴趣。来自不同学科的广泛而多样化的研究生和本科生将参与其中。这项拟议的研究描绘了一个路线图，以理解超越经典案例的流。曲率的作用，一个很大程度上被忽视的方面，通过一个概念框架，结合模拟，连续逼近方法，分岔和流拓扑分析，实验，从数学，动力学和物理的角度进行剖析。然后，(1)考虑简单的二维和三维形状，研究对称破缺、角和变曲率对经典解的影响；(2)最具代表性的案例将进行实验验证；(3)见解将被用于针对生物医学应用的无系绳合成和生物混合微型机器人。结果是一组通过缩放关系、阶段图和概念验证演示捕获的设计原则。此外，还有方法、算法、软件和数据公开提供，以降低准入门槛，从而扩大了这项技术的范围。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。

Artificial and bio-hybrid (partly synthetic, partly biological) miniaturized swimming robots to navigate through the blood stream and deliver drugs have great potential in biomedicine. Viscous streaming is a phenomenon where an oscillating body generates stable, predictable and robust fluid flows that can be used to manipulate the body's local surroundings. Viscous streaming is being proposed for transport, mixing, and particle assembly, and it may be suitable for transport of mini-bots intended for applications in biomedicine. One limitation is that while streaming phenomena are well understood for simple bodies, little is known in the case of complex geometries. This proposal combines modeling and experiments to tackle the knowledge gap that relates viscous streaming to body shape. This knowledge will connect biology and robotics to enhance current capabilities of mini-bots and enables new ones. This research will pave the way to transformative applications such as localized drug delivery, precision manipulation, and fabrication. This is in line with the national need to increase medicine effectiveness as well as competitiveness in manufacturing via advanced computational methods. The proposed research has broad educational impact at the cross-section of fluid mechanics, simulations, robotics, and bioengineering. A set of outreach activities and intuitive learning modules will be designed to spark interest in fluid mechanics and engineering. A broad and diverse group of graduate and undergraduate students from different disciplines will be engaged. This proposed research delineates a roadmap to understand streaming beyond classic cases. The role of curvature, an aspect largely neglected, is dissected from a mathematical, dynamical and physical perspective via a conceptual framework that combines simulations, method of successive approximations, bifurcation and flow topology analysis, experiments. Then, (1) simple 2D and 3D shapes will be considered to investigate the effect of symmetry breaking, corners and variable curvature with respect to classical solutions; (2) most representative cases will be experimentally verified; (3) insights will be exploited in untethered synthetic and bio-hybrid mini-bots targeting biomedical applications. The outcome is a set of design principles captured by scaling relations, phase diagrams, and proof-of-concept demonstrations. This is complemented by methods, algorithms, software and data made publicly available to lower barrier entries, thus broadening the scope of this technology.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.