Low-cost fabrication methods for creating an inertial-based, multiphase microfluidic bioaerosol sampler

Abstract

Selection of a fabrication method for a particular application of microfluidics is often dictated by a set of specific requirements. In this paper, we explore two low-cost, alternative fabrication methods to a photolithography patterned, polydimethylsiloxane (PDMS) casted microfluidic device bonded to glass, and draw comparisons related to the desired parameters and qualities for the fabrication of an inertial-based, multiphase microfluidic bioaerosol sampling device. These desired parameters include optical transparency for visualizing flow conditions, uniform bond quality for a leak free device, good burst pressure capabilities due to high relative air pressures, and medium resolution feature sizes in the microfluidic design scheme (400 µm to 900 µm feature sizes). Sample devices were fabricated to similar dimensions to evaluate performance in capturing 0.49 µm and 1 µm polystyrene (PS) particles suspended in an injected airflow. Devices designed to test the burst pressure were also fabricated. Good burst pressure results were obtained for poly(methyl methacrylate) (PMMA) and pressure-sensitive adhesive (PSA) tape-based devices, with PSA tape offering a high level of design control given its low variance and predictable strength relative to amount of tape area used for the bond. Particle diversion tests were evaluated for similar dimensions of all three types, with PSA tape-based and PMMA-based burst pressure devices outperforming the PDMS-based devices.