EAGER: An Innovative Way to Enhance Cross-Plane Thermal Conductivity of Polymer-Based Thin Films

#1641103电子设备最关键的问题之一是热管理--从纳米级区域散热。由于功率密度的指数增长和器件尺寸的显著减小，热强度急剧增加。热管理成为推动各种重要国防、空间和商业应用的关键瓶颈。开发节能散热技术是提高电子设备节能、性能、可靠性和寿命的关键。热界面材料的革命性对于散热技术的发展至关重要，因为热界面材料的热阻占从器件到空气的总热阻的很大比例。更好的热界面材料，具有较高的跨平面导热系数，可以减少其他部件的尺寸、成本和重量。该项目建议研究垂直排列或受限链的聚合物薄膜，作为热界面材料的潜在创新解决方案。通过提高界面散热的效率，拟议的工作将显著促进全球可持续能源解决方案。研究结果将通过1)面向大学预科学生的外展活动，2)本科生研究活动和非正式讲座，以及3)与行业合作伙伴的合作，向更广泛的受众传播。在目前成功的基础上，PI将尽一切努力促进学术多样性和招收代表性不足的学生。这项建议的研究目标是测试垂直排列或限制在垂直排列的纳米通道中的聚合物链可以增强薄膜的跨平面导热性能的假设，并了解增强的最佳条件(如果有的话)。其目标是加速合理设计具有高跨面导热系数的聚合物或聚合物-无机杂化薄膜，以用于变革性的热应用，例如用于电子热管理的有前途的热界面材料。分子动力学模拟将被用来计算我们感兴趣的薄膜的热导率，以1)建立垂直取向和其他取向(水平取向和非晶膜)之间的基线比较；2)建立结构-性质关系；以及3)通过研究振动模式和量化链的结晶度和限制来理解微观机制。如果这一假设得到证实，这可能会为设计具有高跨面导热系数的聚合物薄膜打开令人兴奋的机会。这项拟议的研究将促进对垂直排列或限制的聚合物基薄膜中热输运的基本理解，并回答垂直排列或限制是否有可能实现高的跨平面导热系数，以及如何优化增强。对这种独特形貌的聚合物薄膜中热输运过程的基础研究突出了这项工作的智力优势。

#1641103Tain, ZhitingOne of the most critical problems with current electronic devices is thermal management - removing heat from nanoscale regions. The heat intensities increase steeply, created by an exponential increase in power densities and a significant decrease in device sizes. Thermal management becomes a critical bottleneck for the advancement of a variety of important defense, space and commercial applications. Developing energy-efficient cooling technologies is the key to improving energy saving, performance, reliability and lifetime of electronic devices. Revolutionizing thermal interface materials is crucial for the development of heat rejection technologies because the thermal resistance of thermal interface materials comprises a significant fraction of the total thermal resistance from device to air. Better thermal interface materials with high cross-plane thermal conductivity allow reduction of size, cost and weight of other components. This project proposes to study polymer-based thin films with vertically aligned or confined chains as a potentially innovative solution to thermal interface materials. By improving the efficiency of heat rejection at the interface, the proposed work will notably contribute to global sustainable energy solutions. The research findings will be disseminated to a broader audience through 1) outreach activities for precollege students 2) undergraduate research activities and casual talks and 3) collaboration with industry partners. Building on current success, the PI will make every effort to promote academic diversity and recruit underrepresented students.The research objective of this proposal is to test the hypothesis that polymer chains, which are vertically aligned or confined in vertically aligned nanochannels, can enhance the cross-plane thermal conductivity of thin films and to understand the optimal conditions for enhancement, if any. The goal is to accelerate rational design of polymer or polymer-inorganic hybrid thin films with high cross-plane thermal conductivity for transformative thermal applications such as promising thermal interface materials for electronics thermal management. Molecular dynamics simulations will be performed to compute the thermal conductivity of thin films of our interest to 1) establish the base line comparison between vertical alignment and other orientations (horizontal alignment and amorphous films); 2) build the structure-property relation; and 3) understand the microscopic mechanisms by investigating the vibrational modes and quantifying the chain crystallinity and confinement. If the hypothesis is proven, this may open up exciting opportunities to engineer polymer-based thin films with high cross-plane thermal conductivity. The proposed study will advance the fundamental understanding of thermal transport in polymer-based thin films with vertical alignment or confinement, and answer whether the vertical alignment or confinement could potentially achieve high cross-plane thermal conductivity and how the enhancement, if any, can be optimized. The fundamental study of thermal transport processes in polymer-based thin films of this unique morphology highlights the intellectual merits of this work.