Multiscale Computational Design of Active Thermal Interfaces Leveraging Quantum Phenomena

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

#1250192 Sinha Research Summary: The project proposes (1) a new concept for interfacial thermal energy transport based on quantum mechanical resonant energy exchange mechanisms active at the nano and atomic scale, and (2) the development of a multiscale computational framework to assess the potential and optimize the design of such an interface. Traditionally, interfacial conductivity is engineered by passive mechanisms, relying on phonon matching to assist conductional across two surfaces. Instead, the project proposes to investigate an additional energy exchange mechanism between the surfaces mediated by resonant dipole-dipole interactions between molecular layers bonded to the two surfaces. The interface concepts explored are electronic and vibrational energy exchange mechanism between a solid and molecular adsorbates, and electronic energy exchange mechanisms between two surfaces in close proximity. Assessing and optimizing the design requires linking multiple scales in thermal transport from angstrom quantum scales to sub-micrometer phonon mean free path scales. Intellectual Merit: It is commonly believed that conventional solid-solid heat conduction offers the best option for thermal transfer across an interface. This work will critically investigate whether active interface design has the potential for enhanced thermal conduction beyond the solid-solid limit. The interface design proposed links a numbers of active phenomena operative at variety of length scales, and inherently requires a multiscale approach. These techniques to be implemented include first-principles methods (density functional theory, quantum Monte Carlo), molecular dynamics simulations, and continuum level modeling based on Maxwell's equations. The team consists of two active researchers in nanoscale transport phenomena and in first-principles modeling of materials. Broader Impact: Across a variety of arenas including microelectronics and large scale applications, interfaces are the limited factor for heat transport. This proposal considers a fundamentally new and potentially transformative approach to interfacial thermal conductional based on resonant energy transfer processes. The research proposed here will also be complemented by a number of synergistic teaching activities: (1) Creating a series of six java applets entitled Nanoscale Thermal Transport at Interfaces meant for use as a university-level teaching tool, that will be made available to educators via PI websites and through publication in an education journal. (2) The proposed research will provide the opportunity for the training and development of two graduate students in the multidisciplinary fields of nanosciences, transport phenomena, and multiscale modeling. (3) Undergraduate researchers will be involved and exposed to this new field of study. (4) For the duration of the program, the PIs will coordinate a full-day workshop, including modeling demonstrations, laboratory tours, and hands-on activities, to take place during the GIRRLS Exploring Science and Engineering Camp, held every summer at the University of Illinois Campus Middle School for Girls. (5) The research findings will be disseminated in peer-reviewed, archival journals and presented at conferences.