EAGER: Parallelized Measurements of Kapitza Resistance

晶界在大多数金属和陶瓷中很常见，晶界的取向会影响材料的导热能力。具有良好导热性的材料在能源应用中很有用，如核反应堆中的陶瓷燃料、热电发电机、从氢中发电的固体氧化物燃料电池，以及用于高功率电子产品的多晶金刚石。测量晶界热阻一直局限于缓慢的逐点测量，导致没有足够的数据来充分了解晶界取向如何影响热传导。该项目旨在开发一种快速、并行的热阻测量装置，该装置基于现有的逐点技术，但同时在100个地点应用。这将使这些测量的速度提高100倍，将测量所需的时间从几个月缩短到几天。拟议的研究可能会通过实现高通量方法来改变热测量领域。除了技术方面，该项目还将吸引研究生和本科生，特别努力从大学的女性工程组招生，并为当地四年级课堂提供示范和教案。如果能够从大型数据集中确定高保真的晶界结构-性质模型，则可以设计核燃料和其他高价值材料的热传输性能，以提高能源生产、可靠性和安全性。这项研究的智力价值在于并行的微观热测量具有潜在的变革性。在实现这一点之前，需要确定热反射技术的并行实现的局限性，以及如何很好地区分感兴趣的属性，如单个颗粒的导热系数、晶界热阻以及颗粒内和晶界附近的缺陷对热传输的作用。为了解决这些问题并实现向新型高通量热表征技术的范式转换，这一迫切需要的项目将专注于：(I)开发基于空间域并行的高通量热表征设备，即热反射方法。(Ii)确定可用拟议的并行表征技术检测到的接触热阻的测量范围和分辨率。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Grain boundaries are common in most metals and ceramics, and the orientation of the grain boundary can impact the ability of the material to conduct heat. Having a material with good heat conduction is useful in energy applications like ceramic fuels in nuclear reactors, thermoelectric generators, solid oxide fuel cells producing electricity from hydrogen, and polycrystalline diamond for high power electronics. Measuring the thermal resistance at grain boundaries has been limited to slow, point-by-point measurements, resulting in not enough data to fully understand how the orientation of the grain boundary affects heat conduction. This project aims to develop a rapid, parallelized thermal resistance measurement device based on existing point-by-point technologies but applying it at 100 sites simultaneously. This would increase the rate at which these measurements are done by 100x, shortening the time needed for measurements from several months to a couple of days. The proposed research can potentially transform the field of thermal measurements by enabling high-throughput approaches. In addition to the technical aspects, this project will engage graduate and undergraduate students with a special effort to recruit students from the university’s Women in Engineering group and provide demonstrations and lesson plans for local 4th grade classrooms.If high-fidelity structure-property models for grain boundaries could be determined from a large data set, the thermal transport performance of nuclear fuels and other high value materials could be designed for enhanced energy production, reliability, and safety. The intellectual merit of this research is the potentially transformative nature of parallelized, microscopic thermal measurements. Before this can be realized, the limitations of a parallelized implementation of thermoreflectance techniques need to be determined, as well as how well the properties of interest can be distinguished, such as individual grain thermal conductivity, grain boundary thermal resistance, and the role of defects within grains and near the grain boundaries on thermal transport.To resolve these issues and achieve the needed paradigm shift to a new class of high-throughput thermal characterization techniques, this EAGER project will focus on: (i) Developing a high-throughput thermal characterization device based on parallelization of a spatial domain, thermoreflectance method. (ii) Determining the measurement range and resolution of thermal contact resistances that can be detected with the proposed parallelized characterization technique.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.