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

人工和生物混合(部分是合成的，部分是生物的)微型游泳机器人可以在血液中导航并输送药物，在生物医学方面具有巨大的潜力。粘性流动是一种现象，在这种现象中，摆动的物体会产生稳定、可预测和强大的流体流动，这些流动可以用来操纵物体的局部环境。粘性流动被提出用于运输、混合和颗粒组装，它可能适合于运输用于生物医学应用的微型机器人。一个限制是，虽然人们对简单物体的流动现象很好地理解，但对于复杂的几何图形，人们却知之甚少。这项建议将建模和实验相结合，以解决粘性流动与体型之间的知识鸿沟。这些知识将把生物学和机器人学联系起来，以增强迷你机器人的现有能力，并使新的能力成为可能。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要。拟议的研究在流体力学、模拟、机器人和生物工程的横截面上具有广泛的教育影响。将设计一套外展活动和直观的学习模块，以激发人们对流体力学和工程学的兴趣。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进来。这项拟议的研究勾勒出了一张路线图，以理解超越经典案例的流媒体。曲率的作用是一个很大程度上被忽视的方面，通过一个结合了模拟、逐次逼近法、分叉和流拓扑分析、实验的概念框架，从数学、动力学和物理的角度剖析了曲率的作用。然后，(1)简单的2D和3D形状将被考虑以研究对称破缺、拐角和变曲率相对于经典解的影响；(2)最具代表性的案例将被实验验证；(3)针对生物医学应用的非束缚合成和生物混合迷你机器人将被挖掘洞察力。其结果是通过缩放关系、相图和概念验证演示获取的一组设计原则。此外，还有公开提供给低门槛参赛项目的方法、算法、软件和数据，从而扩大了这项技术的范围。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.