Liquid-Mediated Adhesion: Forces, Flows and Pressure Limits

1236577Streator这项研究的动机是为了了解小通道内液体施加的拉伸应力，并帮助减轻在微米和纳米尺度器件中普遍存在的“静摩擦”问题。将对规定表面粗糙度的固体之间的液体界面进行流速、张力、表面变形和摩擦力的测量。与实验平行，将开发一个数学模型，该模型考虑弹性变形和毛细效应，以描述接触粗糙弹性表面之间的界面处的薄液膜的流动。这项工作将评估最近发表的数学模型在文献中预测的界面崩溃的概念的有效性。这项调查也将有助于建立新的下限的幅度产生的负毛细压力在狭窄的接口。预计工作结果将与几个技术领域有关，包括与多孔介质中的流动、湿土壤的稳定性、MEMS、磁记录、粘合剂和密封有关的技术领域。此外，该项目将为本科生和大学预科生提供丰富的教育经验。本科研究人员将参与开发一个名为“毛细血管连接”的视频，该视频具有毛细作用的几个物理演示，涉及几个不同的领域，如雨刮片的粘滑行为，植物中水分的上升，粘合剂的功能，以及多孔体（如常见的海绵）的吸收机制。计划通过在YouTube上发布视频，使公众能够获取该视频。利用NSF赞助的步骤计划在格鲁吉亚技术，本科生和研究生的支持下，拟议的项目将访问步骤合作伙伴高中显示和讨论毛细血管连接视频。

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.