A micro flow sensor for volumetric measurement of conductive fluids

We present a microfluidic volumetric measurement system for applications involving conductive fluids. The low cost polydimethylsiloxane (PDMS) device consists of an interconnected Venturi Tube to generate vacuum for fluid manipulation, and a resistance based sensor for fluid volume quantification. The Venturi Tube achieves less than 88 kPa (absolute pressure) vacuum when a 256 kPa external pressure is applied. Measurements using the volumetric sensor have been demonstrated with deionized water, and the results correlate well (R
²
=0.9996) with the micro syringe references. The demonstrated system provides excellent functionality for conductive fluids, such as those used in biomedical applications.