Valve-Based Microfluidics

The human immune system is a complex system that receives myriads of signals from its surrounding environment. These signals can be continuous in nature but at the same time also be variable both in time and concentration. This phenomenon of variable input is quite prevalent as several molecules, e.g. growth factors or signaling molecules, are secreted with variation in time and concentration that in turn affects the action of downstream signaling molecules.

Transcription factors or downstream signaling molecules can demonstrate oscillatory behavior where the detection of signals from the surrounding leads to its activation whilst via inhibitory molecules there is also deactivation. With pulsatile stimulation, where the frequency of input matches the frequency of the oscillation of the signaling molecules, it becomes easier to interpret the behavior of immune cells under different conditions at single-cell level.

Microfluidic designs, integrated with microfluidic large-scale integration technology, is one of the many kinds of microfluidic platforms that allow for complete automation and parallelization of workflow. With the added advantage of being able to program these devices, it is possible to deliver variable input to the immune cells to accurately be able to mimic the cellular microenvironment. At the Laboratory of Immunoengineering, we develop and design multi-layer microfluidic devices for the construction of artificial microenvironments to study cells at single-cell level on-chip in highly automated and controlled manner with the goal to decode cellular activation thresholds and responses.