What Features of a Liquid Contact Layer Help Minimize Thermal Boundary Resistance Near a Crystalline Wall ?

Efforts to miniaturize the size of 3D integrated chips for very power intensive applications like data mining and artificial intelligence continue to face challenges with rapid extraction of waste heat, which can otherwise lead to thermal runaway and chip failure. Although chip cooling using specialty liquids flowing through networks of microfluidic channels offers a viable solution, there remain many open questions regarding the nature of heat transfer across a liquid/solid (L/S) interface. In particular, further studies are needed to better understand how to further reduce the intrinsic thermal boundary resistance across an L/S interface. Given the lack of experimental probes with the necessary spatiotemporal resolution to answer such questions, non-equilibrium molecular dynamics (NEMD) simulations have proven critical in this regard. Here we present results of extensive NEMD studies of a layer of simple liquid confined between two crystalline walls maintained at a constant temperature differential. We focus on aspects of the liquid contact layer that appear to enhance thermal flux. By examining the commensurability between the proximal liquid and solid layers, we identify parameter regimes which closely correlate with a reduction in thermal boundary resistance and an enhanced thermal flux.