Managing heat in modern electronic systems is a growing challenge, especially with the rising power density in applications such as data centers, radar, and high-performance computing. Data centers alone consume vast amounts of energy—about 200 terawatt-hours annually from 2015 to 2021—primarily due to the cooling infrastructure needed to prevent overheating. While current cooling methods, like forced air convection and microchannel cooling, can theoretically manage the high heat fluxes required by today’s electronics, the thermal resistance between the heat source and the cooling medium remains a significant barrier obstacle in practice, limiting the effectiveness of the cooling system. Thermal interface materials (TIMs) are designed to reduce this resistance without additional energy input. Still, their real-world performance often falls short of theoretical predictions, presenting major obstacles in cooling high-power electronic devices (Fig. 1).

Fig. 2. Structure, performance, and application of the colloidal LMs. a) Illustration depicting the mechanochemical effect in designing the heterogeneous AlN-LM interface, forming a gradient diffusion of LMs into the crystal lattice of AlN. b) Scanning electron microscope (SEM) image depicting stable dispersion of AlN particles (1 mm, 15 vol%) in the LM host, even after one month. c) Transmission electron microscopy (TEM) of AlN-LM heterointerface. d) EDS line scans depicting variations in N, Al, Ga, In, and Sn along the marked yellow arrow in the AlN-LM heterointerface. e) Thermal conductivity of colloidal LMs with various mechanochemical times for regulating the LM diffusion in the AlN crystal. f) Exploded view of component modules in the large thermal-management device, comprising a microchannel heat sink, a housing module, and a heating module. Colloidal LM was applied between the heat sink and heat source. g) Average temperature curves of the copper-block heat source as a function of service time, at a coolant flow rate of 2.1 L/min. h) Heat extraction efficiency and pump electricity power of the large-scale microchannel-mediated thermal management system at a heat flux of 100 W/cm².

By optimizing the mechanochemical treatment time, we achieved a cream-like colloid (45 vol% 30 µm AlN) with an interface infiltration depth of 31.50 nm, exhibiting an out-of-plane thermal conductivity of 68.22 W/m·K after just 2 minutes of treatment (Fig. 2e). The interface thermal resistance of the colloidal LMs showed a reduction of more than an order of magnitude compared to conventionally mixed LM/AlN composites. Additionally, when combined with microchannel cooling, our LM colloid demonstrated extremely low thermal resistance across a large thermal interface area of 16 cm², significantly lowering the operating temperatures of a large-scale device running at kilowatt power levels. Under a same heating condition, our material can facilitate a 65% reduction in pump electricity consumption compared to the most advanced TIMs (i.e., thermal grease) (Fig. 2f-h).

This breakthrough moves us closer to realizing the ideal performance predicted by interface theory, offering more sustainable cooling solutions for high-power electronics. Our materials are set to advance cooling in energy-intensive applications, from data centers to aerospace, paving the way for more efficient and eco-friendly technologies.