Pressure-Regulated Direct-Foaming Method for Fabricating 3D Porous Graphene Foam Thermal Interface Materials With High Compressibility and Fingerprint-Level Interfacial Conformability

As electronics shrink and power density rises, effective heat dissipation becomes critical. Thermal interface materials (TIMs) are vital for ensuring the reliability and sustainable operation of next-generation devices. Conventional research typically prioritizes high thermal conductivity as the primary objective. However, the thickness, compressibility, and deformability of TIMs also critically influence heat transfer performance. Here, a novel strategy is reported for fabricating an ultralight 3D porous graphene TIM with high compressibility and low thermal resistance via pore structure control achieved by regulating pressure during foaming. The prepared reduced graphene oxide (rGO) foam combines ultrahigh compressibility (94.85%) and low density with low thermal resistance (0.151 cm²∙K/W under 100 psi) and excellent in-plane temperature uniformity performance, while offering superior conformability to complex mating interfaces. A significant reduction in chip temperature (8.83–13.3°C) is achieved compared to commercial thermal pads (5 W/m·K) at heat dissipation powers of 20–30 W. Furthermore, the manufacturability of these TIMs showcases a promising new approach to TIM fabrication for next-generation, high-power-density electronic devices.