Collaborative Research: Sloshing liquid decontamination of compliant surfaces

远程表面的去污是具有挑战性的，特别是当外部物质的积累阻碍了这些表面的动态功能时。这种表面的一个例子是扑翼机器人的小而灵活的翅膀，它开始接近天然昆虫的规模。利用振动从这些表面去除液体污染物，为自动清洁和干燥提供了机会。然而，在这些尺度上，晃动的液体污染物的运动和它们所停留的柔性表面是耦合的——一方的变形影响另一方。因此，该项目的主要目的是深入了解表面的运动如何影响液滴的运动和喷射。该项目将为将自净化策略应用于其他易受液滴影响的表面（如食品制备和医疗保健领域）提供基础。该项目还包括通过科学展览项目指导和在pi实验室的研究机会，向当地高中生开展外展活动。这个项目的目的是揭示晃动的液体污染和喷出的表面，其中流体和表面运动是高度耦合的物理。这个紧密结合的实验，理论和数值研究将回答高度相互依赖的流体-结构相互作用的问题。这个项目将两个基本系统——一个悬臂和一个液滴——结合在一起，形成一个动态复杂的系统。驱动悬臂基座使其弯曲，跌落到晃动和/或滑动，基材反过来对跌落运动做出动态响应。高速摄像和精确控制的振动输入将能够表征跌落运动和弹射事件，其中固体基材可以在整个振动周期中表现出一系列曲率和加速度。传统的悬臂和弹性动力学将与惯性相关的非保守流体力相结合，以量化这些非平稳过程中的耗散、下降相干性和流体去除。数值将允许耦合的流体和固体控制方程的合成，以确定最有效的激励策略的衬底净化。自净化能力为柔性机翼提供的多功能增加了一个新的维度，对于易受化学物质、水分和生物膜影响的表面的功能至关重要。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。

The decontamination of remote surfaces is challenging, particularly when the accumulation of external matter hinders these surfaces’ dynamic function. An example of such surfaces is the small, flexible wings on flapping-wing robots that are beginning to approach the scale of natural insects. Removing liquid contaminants from these surfaces using vibration presents an opportunity for autonomous cleaning and drying. However, at these scales, the motion of the sloshing liquid contaminants and the flexible surfaces on which they rest are coupled—the deformation of one influences the other. Therefore, the principal aim of this project is to provide a deep understanding of how the motion of a surface impacts the motion and ejection of a liquid drop. This project will provide a foundation by which to adapt self-decontamination strategies to other surfaces vulnerable to droplets, such as those in food preparation and healthcare. This project also encompasses outreach activities to local high school students via science fair project mentoring and research opportunities in the PIs’ labs. The objective of this project is to reveal the physics of sloshing liquid contaminates and ejection from surfaces in which the fluid and surface motions are highly coupled. This tightly integrated experimental, theoretical, and numerical study will answer questions in highly interdependent fluid-structure interaction. This project mates two elementary systems—a cantilever and a fluid drop – to form a dynamically complex system. Driving the cantilever base causes it to bend and the drop to slosh and/or slide, and the substrate dynamically responds in turn to drop motion. High-speed videography and precisely controlled vibratory input will enable the characterization of drop motion and ejection events in which the solid substrate can exhibit a range of curvatures and accelerations throughout the vibration cycle. Conventional cantilever and elastica dynamics will be augmented with inertia-related non-conservative fluid forces to quantify dissipation, drop coherence, and fluid removal in these non-stationary processes. Numerics will permit the synthesis of coupled fluid- and solid-governing equations to determine the most effective excitation strategy for substrate decontamination. The ability to self-decontaminate adds a new dimension to the multi-functionality provided by flexible wings and will be critical to the functionality of surfaces vulnerable to chemicals, moisture, and biofilms.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.