A Real Time Feed Forward Control of Slug Flow in Microchannels

In this work, the authors present a feed-forward control system for two-phase microfluidic processes, widely adaptable for system-on-chip control in a wide variety of bio-chemical experimental conditions, in which two fluids interact in a micro-channel. The proposed approach takes advantage of the optical monitoring of the slugs flow and the on-line signal processing in the frequency domain for slug passage detection. The experimental characterization of the slug flows by the frequencies of the slugs passage was obtained and used to drive the pumps. The open loop control system was designed and implemented in Labview. The platform includes four modules and a GUI. The first manages the communication between the PC and the syringe pumps, while the second is used to implement the control law. The third manages signal acquisition from the photo-diodes and the last implements the soft-sensor for the signal analysis. Wide-reaching experimental design was carried out for characterization and validation of this approach.