In this work, a microfluidic device composed of a capillary glass with a square cross-section and a hydraulic diameter of 800 μm for flow manipulation and control is studied with an experimental and numerical approach. A swirl flow is induced by applying a thermal gradient to the vertical side walls of the microchannel. As a result, it is possible to rapidly manipulate the secondary flow generated by buoyancy phenomena and control the direction of the swirl flow (sense of rotation) by adjusting the temperature gradient. Peltier cells, controlled by an Arduino unit, are used to impose the temperature gradient. To fully characterize the phenomena, the fluid motion inside the channel is analyzed using micro-PIV techniques. Then, the information about velocity and temperature is used to numerically simulate the system. 1