Self-adaptive thermal interface materials featuring low thermal resistance by combining phase change materials with magnetic field-induced filler alignment

Abstract

Thermal interface materials (TIMs) with high thermal conductivity, low thermal resistance, and adaptive capabilities are urgently needed to address the heat dissipation challenges posed by miniaturized electronic devices. However, achieving high through-plane conductivity remains challenging due to difficulties in constructing effective thermal pathways through the thickness of the composite. Furthermore, the mechanical properties of TIMs, which are crucial for enhancing heat dissipation by minimizing contact thermal resistance, are frequently overlooked. Herein, mesophase pitch-based carbon fibers (CFs) at a relatively low content (16 wt%) are vertically aligned in polyethylene glycol (PEG) under a minimal magnetic field (∼0.7 T), resulting in vertically aligned CFs/PEG (VACFs/PEG) composite with an impressive thermal conductivity of 24.24 W/m·K. This composite achieved a temperature reduction of 8.1°C for a LED of 30 W. In addition, the PEG matrix demonstrates adaptive properties at increasing temperatures, contributing to a reduction in thermal resistance to 1.12 cm² K/W. Furthermore, the VACFs/PEG composite exhibits a latent heat of fusion of 118.03 J/g, demonstrating excellent short-term thermal storage performance and promising potential for use in complex thermal management system.