Self-sintering thermal interface material is prepared from a polymer matrix and a filler. The polymer matrix may be a water or hydrogen peroxide or other water-contained solvent solution such as ammonia or alcohol containing a water soluble resin and fumed silica or an alcohol or other solvent solution containing at least one water insoluble resin and fumed silica. The filler contains i) gallium alkali metal or gallium metal, ii) one or more micro/nano-sized metallic fillers, and iii) dielectric fillers.