Plasmonic Heating induced thermocapillary motion of a deformable drop

In this paper, we explore the thermocapillary motion of a droplet in a channel induced by plasmonic heating of the surface. A three-dimensional thermocapillary-driven flow of a bubble in a homogeneous medium enclosed by a structure subject to plasmonic heating has been considered. There have been previous studies on thermo-plasmonic convection in channels induced by plasmonic heating due to frequency-dependent absorption of optical energy by nanostructures coupled to an optically absorptive substrate. To the best of our knowledge, a study of a similar phenomenon to produce variations in surface tension to drive a droplet has not been performed. The droplet is considered to be deformable and has a different fluid viscosity than the surrounding medium. The flow has been assumed to be steady. The effect of the viscosity ratio between the droplet and surrounding medium, the initial position of the droplet relative to the channel centreline along with the frequency of incident light, and spacing of the nano-structure on the droplet migration velocity is also reported.