Pressure-induced tuning of thermal transport in carbon-based composites: Directional control of heat dissipation

Aggressive miniaturization in the electronics industry demands more efficient thermal management for electronic devices. Employing the excluded volume approach, we enhanced thermal conductivity (TC) and manipulated heat dissipation in a polymer composite loaded with a thermally conductive filler—graphene nanoplatelets (GNP)—alone or supplemented with a high-volume filler (diamonds). This yielded a maximum bulk TC of 4.5 W m⁻¹K⁻¹ (no compression). The heat dissipation direction could be controlled by compressing (≥50 bars) the wet composite before curing, resulting in an enhancement of the cross-plane thermal conductivity (for thermal-interface materials) to 12.3 W m⁻¹K⁻¹. For non-compressed samples, in-plane thermal conductivity (for circuit board conformal coatings) was dominant (8 Wm⁻¹K⁻¹). Our holistic approach meets diverse thermal management needs.