Strong yet highly conductive liquid metal composite film constructed via friction induced in-situ synthesis

Contact resistance is a crucial bottleneck for various applications. Liquid metal and its composites can reduce contact resistance of interfaces due to their high conductivity and deformability, yet their mechanical strength is insufficient under external forces. Here, we prepare a deformable liquid-metal-bridged nanogranular composite via friction induced in-situ synthesis, realizing low contact resistance alongside high current density of 1.5 GA/m² and high hardness of 2.6 GPa. This remarkable performance originates from the unique structure: a high fraction ( ~ 66 vol%) of nano-sized conductive ceramic particles bridged by high-surface-tension liquid metal through metallic bonding, which is formed in situ under mechanochemical stimulation during friction. This strategy provides a route to fabricating functional liquid metal composites, shedding light into simultaneous improvement of the mechanical and electrical properties.