ISS: Unmasking contact-line mobility for Inertial Spreading using Drop Vibration and Coalescence

PI: Steen， paul提案号：1637960提议的研究重点是研究固定在振动表面上的液滴的行为。该提案是关于建立一个理论来预测液滴的振荡模式和液滴的动员，同时进行非常仔细的实验来验证微重力条件下的理论发现。在国际空间站（ISS）进行实验的优点是可以集中研究受重力影响的情况。这项工作的结果可以在地球上的医疗、制造、工业和农业过程中得到应用。例如，其中一种工艺是浸没光刻，这是一种重要的技术，可以缩小半导体芯片制造工艺的规模。研究结果可以改善浸没式光刻的基本组成部分惯性扩散工艺，并将半导体制造中的缺陷比现行标准减少10%。这可能会为半导体行业节省10%的成本，每年的成本已经达到数千亿美元。接触线运动的特征在地球上是小而快的，在国际空间站上变得更大更慢，这使得它们可以在那里进行光学成像。提出了国际空间站实验来研究惯性扩散。惯性扩散对地球上的制造、涂覆和成形作业至关重要，但研究起来具有挑战性，并且受到的关注不如粘性扩散。所提出的实验将使接触线迁移率参数得以估计。设想了两种设置。第一个将使用驱动平面法向振荡的机械激振器周期性地迫使附着在基板上的液滴的接触线运动。使用基于电润湿的触发器，第二种设置将诱导瞬态液滴-液滴合并事件，随之而来的是接触线的大面积扫描。迁移率是捕获移动接触线的非平衡动态响应的类物质的现象学参数。一旦测量出来，这个想法就是，移动度可以用来预测其他情况下的惯性扩散。激振器和清扫实验分别代表了强迫和瞬态接触线运动，并将证明迁移率参数的实用性。对移动接触线的预测得到了有限的测试，因为接触线速度很快，而且规模小。国际空间站将揭开这些特征的面纱，并对惯性扩散接触线的高水平流动性理论进行测试。在某种程度上，这个理论与谐振子、薛定谔方程和元素周期表有着惊人的相似之处，对广大学生和公众的教育影响将会增加。此外，实验可以用化学元素周期表的比喻来描述为对“运动元素”的探索。拟议的教育计划将通过开发一个外联模块，将这里进行的研究主题整合到高中学生中，来教导女毕业生成为称职的技术领导者。长期影响是通过培养女性的专业技能和指导技能，扩大女性在STEM领域的参与度，并赋予更多女性研究生追求更高职业目标的权力。第二个影响是继续鼓励年轻女孩在高中学习科学和数学，这样她们就有充分的准备和动力在大学里选择科学专业。

PI: Steen, PaulProposal Number: 1637960The proposed research is focused on the study of the behavior of drops pinned on a surface that vibrates. The proposal is about developing a theory to predict the drop oscillation modes and the mobilization of the drop, while conducting very careful experiments to verify the theoretical findings at microgravity conditions. The advantage of conducting experiments at the International Space Station (ISS) is to focus on cases that are affected by gravity. Results from this work can have applications on Earth in medical, manufacturing, industrial and agricultural processes. For example, one of these processes is immersion lithography - an important technique that has allowed for down-scaling in semiconductor chip manufacturing processes. Results for the proposed work could improve the process of inertial spreading, a fundamental component in immersion lithography, and reduce defects found on semiconductor manufacturing by 10% over current standards. This can potentially lead to cost savings on the order of 10% in the semiconductor industry, which is already worth several hundred billion dollars annually.Features of contact line motions that are small-scale and fast on Earth become larger and slower on the ISS, making them accessible to optical imaging there. ISS experiments are proposed to study inertial spreading. Inertial spreading is vitally important to manufacturing, coating and forming operations on Earth but challenging to study and has received less attention than viscous spreading. The experiments proposed will enable a contact line mobility parameter to be estimated. Two setups are envisioned. The first will periodically force the contact line motion of a substrate-attached drop using a mechanical shaker that drives plane normal oscillations. Using an electrowetting-based trigger, the second setup will induce a transient droplet-droplet coalescence event with consequent large sweeping by contact lines. Mobility is a material-like phenomenological parameter that captures out-of-equilibrium dynamical responses of a moving contact line. Once measured, the idea is that mobility can be used in predictions of inertial spreading in other situations. Shaker and sweeping experiments represent forced and transient contact line motions, respectively, and will demonstrate the utility of the mobility parameter. Predictions for mobile contact lines have received limited testing because contact line speeds are fast with small scale features of importance. The ISS will unmask these features and enable testing of a high-level theory of mobility of inertially-spreading contact lines. To the extent that the theory has rather striking parallels to the harmonic oscillator, to the Schroedinger equation and to the periodic table, educational impact to a broad group of students and public will accrue. Moreover, experiments can be phrased as a quest for "motion elements" using the metaphor with the periodic table of the chemical elements. The proposed education plan will teach graduate women to be competent technical leaders through the development of an outreach module that integrates the themes of the research conducted here to high school students. The long-term impact is to broaden the participation of women in STEM by developing their professional and mentoring skills, and empowering more women to pursue advanced career goals as postgraduates. A secondary impact is to continue to encourage young girls to pursue science and math in high school so that they are well-prepared and motivated to choose scientific majors in college.