On-chip micro pressure sensor for microfluidic pressure monitoring

Abstract In this work, a novel on-chip micro pressure sensor was developed for microfluidic pressure monitoring. Polydimethylsiloxane (PDMS) microfluidic chip contained a working fluid channel with a sealed detection channel beneath it. Any change in pressure in the working fluid channel would change the volume of the detection channel. A mixture of two immiscible fluids was sealed in the detection channel. The pressure of the working fluid can be monitored by measuring the interface displacement of the two fluids in the detection channel. A PDMS film between the working channel and detection channel can avoid cross-contamination between fluids. We acquired a calibration curve of the pressure sensor for measurement and optimized the performance of the sensor through parametric studies. Moreover, two pressure sensors were integrated into a microchip to characterize the pressure drop in the microchannel. The developed pressure sensor is inexpensive and easy to be integrated into microfluidic devices to monitor the flow conditions for cell culture, fluid mixing, and droplet manipulation.