Liquid-Mediated Adhesion: Forces, Flows and Pressure Limits

1236577 streator这项研究的动机是为了了解液体在小通道内施加的拉伸应力，并帮助减轻在微纳米级设备中普遍存在的“粘滞”问题。流速、拉力、表面变形和摩擦力的测量将在具有规定表面粗糙度的固体之间进行。与实验并行，将建立一个考虑弹性变形和毛细效应的数学模型，以描述在接触粗糙弹性表面之间的界面上薄液膜的流动。这项工作将评估最近在文献中发表的数学模型所预测的界面崩溃概念的有效性。这项研究也将有助于建立在狭窄界面中产生的负毛细压力大小的新下限。预计工作结果将涉及多个技术领域，包括与多孔介质流动、湿土稳定性、MEMS、磁记录、粘合剂和密封件相关的技术领域。此外，该项目将为本科生和预科学生提供丰富的教育经验。本科研究人员将参与制作一段题为“毛细管连接”的视频，该视频以毛细管的几个物理演示为特色，涉及几个不同的领域，如雨刷叶片的粘滑行为，植物中的水上升，粘合剂的功能以及多孔体（如普通海绵）的吸收机制。该公司计划将这段视频发布在YouTube上，供公众观看。利用美国国家科学基金会在佐治亚理工学院赞助的STEP项目，由拟议项目支持的本科生和研究生将访问STEP合作高中，展示和讨论毛细管连接视频。

1236577StreatorThe research is motivated by the quest to understand the tensile stresses exerted by liquids within small channels and to help mitigate the problem of "stiction" that is prevalent in micro and nano scale devices. Measurements of flow rate, tensile force, surface deformation and friction force will be performed for interfaces involving liquid interposed between solid bodies of prescribed surface roughness. In parallel with the experiments, a mathematical model will be developed that considers elastic deformation and capillary effects to describe the flow of a thin liquid film at the interface between contacting rough, elastic surfaces. This work will assess the validity of the notion of interface collapse as predicted by recently published mathematical models in the literature. This investigation will also serve to establish new lower bounds on the magnitude of negative capillary pressures generated in narrow interfaces. Results of the work are anticipated to have relevance to several technical areas, including those related to flow in porous media, the stability of wet soils, MEMS, magnetic recording, adhesives, and seals. Additionally, the project will provide enriched educational experiences for undergraduate and pre-college students. Undergraduate researchers will be involved in developing a video entitled "Capillary Connections" that features several physical demonstrations of capillarity, touching on several disparate areas, such as the stick-slip behavior of wiper blades, the ascent of water in plants, the function of adhesives, and mechanisms of absorption in porous bodies (like common sponges). It is planned to make the video publicly accessible by posting at YouTube. Leveraging the NSF-sponsored STEP program at Georgia Tech, undergraduate and graduate students supported by the proposed project will visit STEP partner high schools to show and discuss the Capillary Connections video.