Near-Field Radiation Between a Sphere and Substrates of Different Materials

In order to measure the near-field radiative heat transfer between a microsphere and a substrate, we have developed a sensitive technique using a bi-material atomic force microscope (AFM) cantilever. In this paper, we use this technique to measure the near-field radiation between a silica microsphere and substrates made of different materials (semiconductor, metal and polar dielectric materials). The resulting “Conductance-distance” curves show the presence of the near-field radiation enhancement caused by surface phonon-polaritons.