Pressure induced thermal conduction paths in liquid metal-boron nitride fillered thermal interface materials with high thermal conductivity

Abstract

With the continuous evolution of wearable and mobile devices, flexible electronics, and intelligent thermal management, there is a growing interest in thermal interface materials (TIMs) that combine high thermal conductivity with low modulus for stretchability. However, materials with high thermal conductivity often come with elevated Young's modulus. Here, we have developed a TIMs by combining liquid metal and BN with polydimethylsiloxane (PDMS), achieving a blend of low modulus and high thermal conductivity. To enhance thermal conductivity, we introduced boron nitride sheets as “scalpel”, puncturing the oxide layer of the liquid metal under pressure to establish a continuous thermal path. After pressure induction, the LM-BN/PDMS composite exhibits a thermal conductivity of 4.3 W/(m K), with a Young's modulus of only 193 kPa and a fracture strain of 483%. Furthermore, it demonstrates outstanding thermal stability under multiple thermal shock cycles, indicating significant potential for applications in future thermal management for flexible electronic devices, wearable devices, and beyond.