Collaborative Research: Computations, Modeling and Experiments of Self and Directed Assembly for Nanoscale Liquid Metal Systems

PI: Kondic, Lou / Rack, Phillip d .提案号：1604351 / 1603780本研究的目的是通过模拟、建模和实验的综合方法来研究纳米尺度液态金属液滴在表面上的行为。以可控的方式将这种纳米液滴放置在不同的表面上，对于制造具有独特材料特性的表面非常重要，这些表面可以用于微电子设备、太阳能电池板、光谱学甚至癌症的放射治疗。本研究探讨了纳米级液态金属细丝的崩溃与破裂过程中相互竞争的毛细管力、粘性力和惯性力，液态金属与衬底的相互作用，以及通过模板和温度相关的材料特性施加纳米级热梯度的热效应。该提案的变革方面在于为具有增强功能的复杂和多组分纳米颗粒合成的新兴领域提供新的见解。在本工作中提出的研究工作重点是开发直接数值方法来解决全三维Navier-Stokes方程，并结合目标实验。具体来说，精确的数值方法将基于流体的多材料体积方法，也包括三重结和移动接触线，以及描述液固相互作用的势。为了挑战计算，设计了物理实验来询问各种金属/合金-衬底组合，这将探测相关的水动力和化学不稳定性。该方案的一个显著特点是数值结果与实验结果的直接比较。理论、计算和实验工作将相互推动，理论预测将直接由实验验证，随后这些实验将用于对纳米级液态金属的不稳定性和输运进行更准确的理论描述。这项研究的结果将对广泛的探索实验和计算流体动力学的社区以及更广泛地考虑纳米科学各个方面的研究人员感兴趣。所提出的工作的更广泛的影响在于为具有增强功能的复杂和多组分纳米颗粒合成的新兴领域提供新的见解。拟议的工作预计将对许多应用程序产生影响。例子包括用于增强太阳能电池和波导的基于金属粒子的等离子体结构，在这些结构中，有一个由有序的金属纳米颗粒阵列覆盖的衬底是令人感兴趣的。该提案还包括开发软件，供社区研究人员使用，并为研究生和本科生开展教育活动。

PI: Kondic, Lou / Rack, Phillip D.Proposal Number: 1604351 / 1603780The goal of the proposed research is to investigate the behavior of nanoscale liquid metal drops on surfaces with a comprehensive approach of simulations, modeling and experiments. Placing such nanodrops on different surfaces in a controlled way is important for manufacturing surfaces with unique material properties that can be used in microelectronic devices, in solar panels, in spectroscopy and even in radiation treatment for cancer.The proposed work explores competing capillary, viscous and inertial forces in the collapse versus breakup of nanoscale liquid metal filaments, liquid metal-substrate interactions, and thermal effects where nanoscale thermal gradients will be imposed via templating and temperature dependent material properties. The transformative aspect of this proposal resides in providing new insights into the emerging field of complex and multi-component nanoparticle synthesis with enhanced functionality. Research efforts put forward in this proposed work focus on developing direct numerical methods for solving fully 3D Navier-Stokes equations in combination with targeted experiments. Specifically, accurate numerical methods will be developed based on the multi-material Volume of Fluid approach, also incorporating triple junctions and moving contact lines, as well as the potentials describing liquid-solid interactions. To challenge the computations, the physical experiments are designed to interrogate various metal/alloy-substrate combinations which will probe the relevant hydrodynamic and chemical instabilities. A distinguishing feature of the proposed project is the immediate and direct comparison of numerical results with the experimental ones. The theoretical, computational, and experimental work will drive each other, with theoretical predictions directly checked by experiments, and subsequently these experiments will be used to develop more accurate theoretical description of the instabilities and transport of nanoscale liquid metals. The results of this research will be of interest to a wide community exploring experimental and computational fluid dynamics and more generally to the researchers considering various aspects of nanoscience. The broader impact of the proposed work resides in providing new insights into the emerging field of complex and multi-component nanoparticle synthesis with enhanced functionality. The proposed work is expected to have an impact on a number of applications. Examples include metal-particle based plasmonic structures for enhanced solar cells and waveguides, where it is of interest to have a substrate covered by ordered arrays of metallic nanoparticles. The proposal also includes the development of software that will be available to researchers in the community, and educational activities for graduate and undergraduate students.