Magnetically-Functionalized Self-Aligning Graphene Fillers for High-Efficiency Thermal Management Applications

TL;DR

This paper introduces magnetically functionalized graphene fillers that can be aligned in thermal interface materials to significantly enhance heat conduction, offering a scalable and effective solution for thermal management in electronics.

Contribution

The study presents a novel method for aligning graphene fillers in thermal composites using magnetic functionalization, leading to doubled thermal conductivity improvements.

Findings

Thermal conductivity increased by a factor of two with oriented fillers.

Temperature rise in computer chips decreased by up to 10°C.

Magnetic alignment significantly improves heat transfer in nano-composites.

Abstract

We report on heat conduction properties of thermal interface materials with self-aligning "magnetic grapheme" fillers. Graphene enhanced nano-composites were synthesized by an inexpensive and scalable technique based on liquid-phase exfoliation. Functionalization of graphene and few-layer-graphene flakes with Fe3O4 nanoparticles allowed us to align the fillers in an external magnetic field during dispersion of the thermal paste to the connecting surfaces. The filler alignment results in a strong increase of the apparent thermal conductivity and thermal diffusivity through the layer of nano-composite inserted between two metallic surfaces. The self-aligning "magnetic grapheme" fillers improve heat conduction in composites with both curing and non-curing matrix materials. The thermal conductivity enhancement with the oriented fillers is a factor of two larger than that with the random fillers even at the low ~1 wt. % of graphene loading. The real-life testing with computer chips demonstrated the temperature rise decrease by as much as 10oC with use of the non-curing thermal interface material with ~1 wt. % of the oriented fillers. Our proof-of-concept experiments suggest that the thermal interface materials with functionalized graphene and few-layer-graphene fillers, which can be oriented during the composite application to the surfaces, can lead to a new method of thermal management of advanced electronics.