A thermal interface material (TIM) using high thermal conductivity nano-particles, particularly ones with large aspect ratios, for enhancing thermal transport across boundary or interfacial layers that exist at bulk material interfaces is disclosed. At least one of the interfacial layers is a vertically aligned metal nanowire array. The nanoparticles do not need to be used in a fluid carrier or as filler material within a bonding adhesive to enhance thermal transport, but simply in a dry solid state. The nanoparticles may be equiaxed or acicular in shape with large aspect ratios like nanorods and nanowires.