Single particle manipulation/sorting through the transient response of thermocapillary convection flows

In this paper, studies on the transient behavior of thermocapillary convection flows, generated with a single IR laser beam of 1470 nm in wavelength, as a micromanipulation technique are presented. The transient regime was first simulated using COMSOL Multiphysics showing that the flows start having their toroidal shape in less than 100 ms. Then experiments were conducting to measure the influence of the convection cell growth on beads initial motion. With this, the radius of the convection cell was determined in its transient regime. By exploiting this regime, the separation of single beads from a set of them was successfully achieved overcoming the natural toroidal shape of the flows.