Virtual vortex gear

An interesting phenomenon of microfluidic vortices rotating and transmitting like a set of gears has been experimentally observed and is named “Virtual Vortex Gear”. We found that the vortices could be serially induced by increasing the driving pressure. Every two closed by vortices were having opposite directions of the swirling. The relation between the vortices and driving pressure has been evaluated based on the results. The computational simulation revealed that the flow in the connecting channel moves like a 3D spiral and only happens in a particular range of channel height. A potential application of the phenomenon is demonstrated.