Vortex generation and sensing in microfabricated surface channels

We realized a structure that is able to generate vortices inside a microfluidic channel. The structure is compatible with surface channel technology, enabling integration with other devices on the same chip. Characterization of the structure is done by scanning the top membrane of the channel using laser Doppler velocimetry. A novel method for finding the phase relation between the incoherent measured scan points is developed. Initial measurements show that the structure is able to act as a vortex flow sensor, since the vortex frequency is dependent on the flow velocity, making this the first microfluidic vortex flow sensor with a characterized range from 735 mg/h to 1335 mg/h with a sensitivity of 100 Hz/(mg/h). The structure can also be used for passive mixing