Bioinspired Non‐Embrittling Phase‐Inverted Oil‐in‐Liquid Metal Thermal Grease as a High‐Performance Thermal Interface Material

ABSTRACT The demand for compactness and high performance in electronic devices has spurred the miniaturization of electronic chips; however, this comes at the expense of escalated heat generation, requiring efficient heat dissipation. Gallium‐based liquid metals are promising for thermal management due to their metallic thermal conductivity and ability to make intimate contact with surfaces; however, they are limited by certain factors such as leakage, wettability, embrittlement, and alloying, which can deteriorate their performance. Herein, we introduce a liquid metal‐based thermal grease achieved through a phase‐inverted oil‐in‐liquid metal/silicon carbide emulsion process as a potential material for efficient thermal management of electronic chips. The thermal grease, consisting of oxidized liquid metal foam with interstitial voids, fills with silicone oil containing liquid metal particles and silicon carbide particles, exhibits a high thermal conductivity of 9.27 W/(m·K). In addition, a thin silicone oil layer formed spontaneously on the surface of the thermal grease acts as a barrier, preventing liquid metal–metal surface interactions, thereby showing no signs of embrittlement on the aluminum surface for four weeks. This layer is inspired by fish skin, which forms an antibiofouling layer through mucus secreted from the mucous gland. In addition, the rheology of thermal grease prevents unwanted flowability, mitigating the possibility of liquid metal leakage.