Enhanced thermal conductivity and reduced thermal resistance in carbon fiber-based thermal interface materials with vertically aligned structure

As electronic devices advance, there's a critical need for thermal interface materials (TIMs) with high thermal conductivity and minimal thermal resistance to address thermal dissipation challenges effectively. Carbon fibers (CFs), known for their axial thermal conductivity, are ideal for creating high-performance TIMs in a vertically aligned structure, aligning with the TIMs' heat transfer direction. Despite advancements in CF alignment for improved thermal conductivity, the high thermal resistance and the need for cost-effective manufacturing remain challenges. We propose a novel sandwich structure integrating vertical heat transfer pathways with surface modification to tackle these issues. This structure features a core of vertically aligned CF composite, achieved through a rolling-press method, flanked by liquid metal-modified layers to reduce contact thermal resistance. Our composites demonstrate an exceptional through-plane thermal conductivity of 51.90 W m⁻¹ K⁻¹ at 73.68 wt% filler content, 323 times higher than that of the PDMS matrix, and a reduced total thermal resistance from 0.55 to 0.32 K cm² W⁻¹ after interface modification. This research offers insights into designing CF-based composites for enhanced thermal management, applicable in cloud computing and autonomous driving.