The 6th International Symposium
on Thermal-Fluid Dynamics

2025 July 24-27,Qingdao,China

The 6th International

Symposium on Thermal-Fluid Dynamics

(ISTFD 2025)

24-27 July 2025, Qingdao, China

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Dr. Qing-Yao Luo


The School of Engineering, The University of Tokyo, Japan


E-mail:


Bio

Dr. Qing-Yao Luo is a Specially Appointed Researcher at the School of Engineering, The University of Tokyo. He received his Master’s degree in Engineering Thermophysics from Xi’an Jiaotong University, and his Ph.D. in the same field from Tohoku University. His current research focuses on nanoscale interfacial heat transfer, thermal management in electronic devices, and electro-osmotic flow at the nanoscale, using molecular dynamics simulations as a primary tool.

Title

Surface Heterogeneity Effects on Thermal Transport across Solid--Liquid Polymer Interfaces: A Molecular Dynamics Study

Abstract

Efficient heat dissipation at solid–liquid interfaces is a pressing challenge in modern electronic devices, especially as device dimensions approach the phonon mean free path scale. At this nanoscale, interfacial thermal resistance (ITR) becomes a dominant bottleneck, limiting thermal management and device reliability. This keynote presents a systematic investigation into how various forms of surface heterogeneity influence ITR at solid–polymer liquid interfaces, using non-equilibrium molecular dynamics (NEMD) simulations. Three representative types of surface heterogeneities were explored:hard morphological heterogeneity (surface grooves), chemical heterogeneity (patchy wettability patterns), and soft morphological heterogeneity (mixed-length self-assembled monolayers). Our research reveals that surface roughness, when properly scaled relative to the liquid molecule size, can enhance heat transfer by increasing interfacial contact and enabling favorable molecular orientations. Conversely, large-scale chemical patterns lead to temperature non-uniformity across the interface and increased ITR, while smaller patterns yield more homogeneous thermal profiles and reduced resistance. For SAM-based surfaces, stiff and patterned SAMs improve liquid contact and reduce ITR, whereas soft and overlapping SAMs can hinder hydrogen bonding and raise thermal resistance. We conclude with practical design guidelines for ITR control, such as tuning surface topography and chemical patterning to match polymer chain characteristics, and engineering SAM stiffness and composition for optimal liquid interaction. These insights pave the way for more efficient thermal interface engineering in next-generation nanoscale electronic and optoelectronic devices.