We show how the flow from two or three pumps is stable in at low flow speed and in microfluidic devices. In Video S2, we used two 5 mL syringes for delivering 50 µL at a speed of 5 µL/min in a PDMS/Glass microfluidic Y-channel 2 mm wide and with a height of 0.5 mm. Even using such a large syringe, the laminar flow between the two flows is barely disturbed during the experiment. Similarly, we used three 10 mL syringes for flowing 50 µL at 25 µL/min in a three-way-in single PDMS microfluidic channel 1 mm wide and 0.25 mm height. Also in this case the three flows are barely disturbed at their interfaces. We also succeeded in forming a multiphase system using the same three way in microfluidic device, where two inlets were used for flowing oil, and the central channel was used for the water phase (VideoS3). In this case, we used three syringe pumps delivering 50 µL at a speed of 25 µL/min