Abstract

Marangoni flow has recently gained much attention for applications in the particle handling in microfluidic channels. This flow is driven by a surface tension gradient along a vapor-liquid interface, which is induced by temperature gradient along the interface. In our previous study, we generated rapid Marangoni vortex flows around a micro bubble using the thermoplasmonic effect of gold nanoparticles under laser illumination [1]. By holding the laser power constant, stable vortex flows developed around the bubble and tracer microparticles dispersed in the fluid were tidily arranged in a circular pattern. Since the induced flow pattern is sensitive to the laser power, we expect that advanced manipulation of micro particles is realized by temporally modulating the laser power. In this presentation, we focus on the clustering of the tracer particles in the temporally controlled thermoplasmonic Marangoni flows.

© 2015 Japan Society of Applied Physics, Optical Society of America