Thermal Transport Mechanisms at Nanoscale Point Contacts


L. Shi and Majumdar, A., “Thermal Transport Mechanisms at Nanoscale Point Contacts,” J. Heat Transfer, vol. 124, pp. 329–337, 2002.


We have experimentally investigated the heat transfer mechanisms at a 90610 nm diameter point contact between a sample and a probe tip of a scanning thermal microscope (SThM). For large heated regions on the sample, air conduction is the dominant tipsample heat transfer mechanism. For micro/nano devices with a submicron localized heated region, the air conduction contribution decreases, whereas conduction through the solid-solid contact and a liquid meniscus bridging the tip-sample junction become important, resulting in the sub-100 nm spatial resolution found in the SThM images. Using a one dimensional heat transfer model, we extracted from experimental data a liquid film thermal conductance of 6.761.5 nW/K. Solid-solid conduction increased linearly as contact force increased, with a contact conductance of 0.7660.38 W/m2-K-Pa, and saturated for contact forces larger than 38611 nN. This is most likely due to the elasticplastic contact between the sample and an asperity at the tip end. @DOI: 10.1115/1.1447939# Keywords: Contact Resistance,