Morphology-Controllable Liquid Metal/Diamond Sandwich-Structured Thermal Interface Material toward High-Efficiency Thermal Management

With the exponential growth of AI computing power, the power density of electronic devices has exceeded 1 kW/cm², rendering traditional thermal management materials insufficient to handle the challenges of high heat flux density. Developing thermal interface materials (TIMs) with both high thermal conductivity (≥10 W m^-1 K^-1) and interface compatibility is crucial. This study introduces a dual-level interface engineering strategy, constructing a thermally conductive adhesive layer with low interfacial thermal resistance (4 K mm² W^-1) and excellent electrical insulation properties (2.25 × 10¹³ Ω cm) through the incorporation of liquid metal (LM) microspheres (average particle size: 6.4 μm) and micron-sized diamond blending. By combining shear-induced in situ formation of a nanoscale gallium oxide interfacial layer with gradient rotational speed control, a three-dimensional continuous thermal conductive network composite material was successfully fabricated, achieving an ultrahigh thermal conductivity of 237.9 W m^-1 K^-1. The "sandwich" packaging structure effectively mitigates the risk of LM leakage. When applied to high-power devices, the surface temperature of the heat source decreases by up to 69% compared to without TIMs. Further development of the through-plane heat transfer and in-plane waste heat conversion device allows the conversion of waste heat into a stable voltage output of 7.35 V. This marks the successful transition of TIMs from heat dissipation to energy regeneration functionality. This study presents material solution for high-power electronic thermal management and advances the practical application of LM composite materials.