Stratified two-phase microfluidic device for continuous sampling of sub-micron aerosolized particles

Abstract

Growing concerns about public health and national security necessitate the development of compact, integrated systems capable of continuous, real-time collection and detection of biothreats (e.g., viruses and bacteria). In this work, we report an inertial microfluidic-based aerosol capture device for the real-time collection and analysis of airborne particles (e.g., biothreats), motivated by the need for rapid detection capabilities. A two-stage spiral microchannel is designed, fabricated, and evaluated for capturing aerosolized particles with diameters ranging from 0.20 to 1.60 μm, and its performance is compared to a traditional U-shaped microchannel. The spiral microchannel design is developed with the aid of multiphase computational fluid dynamics (CFD) simulations and tested experimentally to investigate the flow dynamics and particle capture efficiencies. Overall, the experimentally measured particle capture efficiencies agreed well with the simulation results and the two-stage spiral microchannel resulted in significant improvement over the traditional U-shaped microchannel. Both the simulations and experiments on the spiral microchannel design demonstrated approximately a two-fold increase in diversion efficiency and a five-fold increase in entrapment efficiency, on average, while having less than a two-fold increase in pressure drop. The performance improvement in the two-stage spiral microchannel design suggests a promising avenue for the development of next-generation devices capable of providing real-time collection and enrichment of aerosolized biothreats.