Photothermal effects induced by the absorption of focused laser light enable the experimental generation of micro- and nanoscale heat sources in fluids or on solid walls of flow channels. Such localized heating induces various thermo-fluidic phenomena, including not only thermal convection, but also thermos-osmotic flows near boundaries and thermophoresis of dispersed particles in fluids. In this study, we present a simple model that incorporates these thermally-induced flows driven by photothermal effects in a fluid confined between two parallel plates. Semi-analytical solutions for temperature and flow fields in the proposed model are also provided. As an application of the semi-analytical solutions, we analyze microflows induced by quasi-point-like heat sources which have been reported in previous studies. We validate the present model and the semi-analytical solution by comparing the results with those of the previous studies, and also show the importance of the thermo-osmotic slip flows in such thermally-induced microflows.
TSUJI et al. (Wed,) studied this question.