3D printed microcyclones for enhanced collection, separation, and recovery of sub-micrometer bioaerosols.

The collection and separation of aerosols is necessary to support the capture and analysis of particulate matter that can impact human health, enabling effective monitoring and prediction of exposure risk, and supporting fundamental studies of aerosol generation, transport, and distribution. Of particular concern are sub-micrometer particles which can deeply infiltrate the lungs, but efficient separation and capture of these smaller particles is challenging. In the case of bioaerosols, effective recovery of biological particles following capture often involves significant dilution of the collected sample, hindering downstream analysis. Here we report a miniature 3D printed cyclone-based platform capable of highly effective separation and recovery of submicron bioaerosols with well-defined cut-off sizes. Using a set of geometrically similar microcyclones fabricated at different size scales, with minimum channel dimensions of 0.75 mm, cut diameters as low as 0.05 μm are achieved at aerosol flow rates up to 5 L/min, with sharp cut-offs yielding nearly 100 % capture efficiency for larger particulates. Furthermore, captured influenza virus is recovered from the devices with up to 85 % efficiency and minimal dilution via a rapid elution process that takes advantage of the low internal microcyclone volume. The high capture efficiency for submicron particles enabled by the microcyclone platform, together with its compact form factor, effective sample recovery, tunable cut size, and cost-effective manufacture, makes the technology a promising tool for broad applications in aerosol and bioaerosol monitoring.