CAREER: Uncover contact line dynamics during thin film evaporation on micro/nano-engineered surfaces with combined velocimetry, thermometry, and interferometry

职业：结合测速、测温和干涉测量，揭示微/纳米工程表面薄膜蒸发过程中的接触线动力学

• 批准号: 2144802
• 负责人: Yaofa Li
• 金额: $ 59.57万
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144802&HistoricalAwards=false
• 关键词: CAREER; Uncover; contact; line; dynamics

Computers and electronics with ever-increasing power densities have become an indispensable part of our daily life to support our learning, communication, driving, and other applications. Effective thermal management technologies are essential to cool these devices to a safe temperature to sustain their high performance. Thin film evaporation, based on continuous evaporation of very thin films of liquid coolant, is a promising cooling strategy due to its simple design, high cooling capacity, and high stability. By incorporating micro/nano-structures such as micro-pillars and nano-pores, the cooling capacity of thin film evaporation has been significantly improved in recent years but is still much lower than theory predictions, due to the lack of fundamental understanding, especially the detailed flow and thermal characteristics at microscopic and nanoscopic scales. This CAREER project seeks to study fluid flow and thermal transport processes at evaporating interfaces by accurately measuring the flow speed, film shape and temperature within thin coolant films that are typically a few micrometers thick. The knowledge gained will be integrated into educational and outreach activities by establishing a thermal-fluid instructional laboratory at Montana State University and creating educational materials targeting the general public and school children with a special emphasis on those from rural communities and underrepresented groups. The overarching goal of this project is to advance the fundamental understanding of the flow, thermal transport, and contact line dynamics at evaporating interfaces via quantifying 3D velocity fields, interface temperature, and interface profile, enabled by innovative experiments and modeling efforts. Specifically, the project team will (i) employ combined astigmatism particle tracking velocimetry, fluorescence thermometry and interference microscopy to perform measurements on micro-structured surfaces, (ii) quantify film temperature and meniscus dynamics within nanopores using nanoscale quantum dot thermometers and environmental scanning electron microscopy, and (iii) develop a microscale model for thin film evaporation on micro-structured surfaces with improved accuracy by incorporating Marangoni flows. The research will characterize the wicking dynamics, liquid-vapor interface temperature, curvature and meniscus dynamics of thin evaporating films with high spatial and temporal resolutions, which will allow precise determination of the accommodation coefficient and the quantification of Marangoni effects, thus filling in current knowledge gaps and informing the next generation of predictive tools.This project is jointly funded by the Thermal Transport Processes Program and the Established Program to Stimulate Competitive Research (EPSCoR).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.

功率密度不断提高的计算机和电子产品已成为我们日常生活中不可或缺的一部分，以支持我们的学习，通信，驾驶和其他应用。有效的热管理技术对于将这些设备冷却到安全温度以维持其高性能至关重要。薄膜蒸发是基于非常薄的液体冷却剂膜的连续蒸发，由于其设计简单、冷却能力高和稳定性高，因此是一种有前途的冷却策略。通过引入微柱和纳米孔等微/纳米结构，近年来薄膜蒸发的冷却能力得到了显着提高，但仍远低于理论预测，这是由于缺乏基本的理解，特别是微观和纳米尺度下的详细流动和热特性。该CAREER项目旨在通过精确测量通常几微米厚的薄冷却膜内的流速、膜形状和温度来研究蒸发界面处的流体流动和热传输过程。将通过在蒙大拿州立大学建立一个热流体教学实验室，并制作针对一般公众和在校儿童的教育材料，特别强调来自农村社区和代表性不足群体的教育材料，将获得的知识纳入教育和外联活动。该项目的总体目标是通过量化3D速度场，界面温度和界面轮廓，通过创新的实验和建模工作，推进对蒸发界面处的流动，热传输和接触线动力学的基本理解。具体而言，项目团队将（i）采用组合的散光粒子跟踪测速法，荧光测温法和干涉显微镜对微结构表面进行测量，（ii）使用纳米级量子点温度计和环境扫描电子显微镜量化纳米孔内的薄膜温度和弯月面动力学，以及（iii）通过结合Marangoni流，开发具有改进的精度的微结构表面上的薄膜蒸发的微尺度模型。该研究将以高空间和时间分辨率表征薄蒸发膜的芯吸动力学、液-汽界面温度、曲率和弯月面动力学，这将允许精确确定调节系数和量化Marangoni效应，从而填补了当前的知识空白，并为下一代预测工具提供了信息。该项目由热传输过程计划联合资助该奖项反映了NSF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。

项目成果

Design and fabrication of a novel on-chip pressure sensor for microchannels

一种新型微通道片上压力传感器的设计和制造

• DOI: 10.1039/d2lc00648k
• 发表时间: 2022
• 期刊: Lab on a Chip
• 影响因子: 6.1
• 作者: Raventhiran, Nishagar;Molla, Razin Sazzad;Nandishwara, Kshithij;Johnson, Erick;Li, Yaofa
• 通讯作者: Li, Yaofa