Controllable thermal transport through nanoscale liquid bridging

The ability to actively control thermal transport rates across interfaces or through materials would enable a number of advanced thermal management strategies. We demonstrate an approach to produce a composite material system with controllable thermal conductivity for thermal switching. Heat transfer across nanostructured materials like nanoparticle packed beds is dominated by the high thermal resistance at contacts between particles. When liquid layers form between those nanoscale solid contacts, due to vapor condensation in the nanoparticle bed, the thermal resistance between the particles decreases dramatically. Varying the size of these nanoscale liquid bridges enables us to actively control the thermal conductivity of the material. We demonstrate an ability to repeatedly increase and decrease nanoparticle bed conductivity by up to a factor of 39 times. This approach to producing a variable conductivity material system shows promise for controlling heat transfer in a wide variety of applications. Published under license by AIP Publishing.