Collaborative Research: Sloshing liquid decontamination of compliant surfaces

偏远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上的小而灵活的翅膀，它们开始接近自然昆虫的规模。使用振动从这些表面去除液体污染物为自主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在的弹性表面是耦合的--其中一个的变形影响另一个。因此，这个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。该项目将提供一个基础，使自去污策略适用于其他易受飞沫影响的表面，如食品制备和医疗保健中的表面。该项目还包括通过科学博览会、项目指导和在私人投资机构的实验室进行研究的机会，向当地高中生开展外展活动。该项目的目标是揭示液体的晃动、污染和从流体和表面运动高度耦合的表面抛射的物理过程。这项紧密结合的实验、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。该项目将两个基本系统--悬臂和液滴--配对，形成一个动态复杂的系统。驱动悬臂基座会使其弯曲，并使下落晃动和/或滑动，并且基板对下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液滴运动和弹射事件，在这些事件中，固体衬底可以在整个振动周期中表现出一定范围的曲率和加速度。传统的悬臂梁和弹性力学将通过惯性相关的非保守流体作用力来增强，以量化这些非平稳过程中的耗散、液滴一致性和流体去除。数值计算将允许合成耦合的流体和固体控制方程，以确定最有效的衬底去污激励策略。自去污能力为柔性机翼提供的多功能增加了一个新的维度，对于易受化学品、湿气和生物膜影响的表面的功能至关重要。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。

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.