Fundamental effects in nanoscale thermocapillary flow

Abstract

When implemented on the nanoscale, material flows driven by gradients in temperature, sometimes known as thermocapillary flows, can be exploited for various purposes, including nanopatterning, device fabrication, and purification of arrays of single walled carbon nanotubes (SWNTs). Systematic experimental and theoretical studies on thermocapillary flow in thin polymer films driven by heating in individual metallic SWNT over a range of conditions and molecular weights reveal the underlying physics of this process. The findings suggest that the zero-shear viscosity is a critical parameter that dominates the dependence on substrate temperature and heating power. The experimentally validated analytical models in this study allow assessment of sensitivity to other parameters, such as the temperature coefficient of surface tension, the thermal interface conductance, and the characteristic length scale of the heated zone.