Laser-induced surface tension alteration in liquids

High-intensity, short-pulse laser radiation interacting with a liquid can impart significant amounts of thermal energy in a small, localized region, which can cause surface-tension-driven flow, i.e., Marangoni convection. Both weakly and strongly absorbing liquids can exhibit this effect. This work investigates the temperature rise during highintensity, short-pulse laser heating of liquids, and the subsequent fluid flow resulting from the laser heating. For the fluid dynamics, a scaling analysis is performed to simplify the incompressible Navier-Stokes equations and identify important parameters, such as the maximum temperature rise, thickness of the laser heated region, and thermophysical properties of the liquid. A simple analysis to determine the behavior of thermal-based laser-induced flows is found to agree well with experimental data from the literature. Technologies that may benefit from laser-induced surface tension alteration and the subsequent flow are discussed.