Advanced Liquid‐metal Thermal Interface Materials via Gelation

ABSTRACT Thermal interface materials (TIMs) based on liquid‐metal combine high thermal conductivity and conformability, but low mechanical strength and poor stability under dynamic loading limit their use. Here we employ an ultrathin porous polymer film, featuring a robust network with 100 nm nanopores for nanoscale confinement, as a structural scaffold to fix liquid‐metal like gel. Sputtered‐metal particles on the surface of the polymer film improve wetting and compatibility, enabling uniform infiltration and stabilization of liquid metal. The resulting metal–like gels reach a tensile strength of 117 MPa, the highest reported for TIMs, while retaining good flexibility. They can be made as ultrathin liquid‐metal gel films (≤2 µm), yielding ultralow bond‐line thickness and an interfacial thermal resistance of 6.1 mm 2 ·K·W − 1 at 80 psi. Excellent stability against pressure, folding, solvent exposure, and thermal cycling addresses key reliability barriers for advanced cooling applications.