Day 20

Stopping the Flow in a Microchannel without Disturbances

When implementing different applications in a microchannel, it is typically needed not only to bring liquids into the channel, but sometimes also to stop the flow. For instance, if you want to observe cells, molecules or proteins in the field of view of your microscope for a longer period of time. 

While using syringe pumps, there can be some difficulties to do so, e.g. you may need addional time, since usually in such systems the flow does not stop immediately and a risk of bubble formation should also be considered. As a solution, an additional on/off valve can be integrated into the setup or onto the chip. Still, it makes the setup more complicated. 

Our pressure-driven flow control allows to stop the flow immediately without on/off valves.

We realised an experiment for stopping the flow with our pressure controller in a microchannel with a diameter of 100 µm with 1µm latex beads. Afterwards the Brownian motion can be observed.