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并提供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、可预测和鲁棒的流体流动的现象，其可用于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小型机器人的运输。一个局限性是，虽然流现象是很好地了解简单的机构，在复杂的几何形状的情况下知之甚少。该建议结合了建模和实验，以解决与粘性流的身体形状的知识差距。这些知识将连接生物学和机器人技术，以增强微型机器人的现有能力，并实现新的能力。这项研究将为变革性应用铺平道路，如局部药物输送，精确操作和制造。这符合国家通过先进的计算方法提高药物有效性和制造业竞争力的需求。拟议的研究在流体力学，模拟，机器人和生物工程的横截面具有广泛的教育影响。将设计一套推广活动和直观的学习模块，以激发对流体力学和工程的兴趣。来自不同学科的研究生和本科生的广泛和多样化的群体将参与。这项拟议的研究描绘了一个路线图，以了解流超越经典的情况。曲率的作用，很大程度上被忽视的一个方面，解剖从数学，动力学和物理的角度通过一个概念框架，结合模拟，逐次逼近，分叉和流动拓扑分析，实验的方法。然后，（1）将考虑简单的2D和3D形状，以研究对称性破缺、拐角和可变曲率对经典解决方案的影响;（2）将对大多数代表性案例进行实验验证;（3）将在针对生物医学应用的无约束合成和生物混合微型机器人中利用见解。结果是一组设计原则，通过缩放关系，相图和概念验证演示来捕获。该奖项反映了NSF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.