Continuous aerosol size separator using inertial microfluidics and its application to airborne bacteria and viruses

Abstract

A microchannel-based aerosol size separator that separates submicron aerosols according to particle inertial differences and Dean vortices in the airflow was developed for use in low-cost, portable, real-time aerosol collectors, detectors, concentrators and other such devices. The microfluidic inertial separator was furthermore applied to simultaneously separate airborne microorganisms by size, such as airborne viruses and bacteria from larger aerosols and viral particles from bacterial cells. The entire system was designed by numerical simulation and analysis. In addition, its performance was evaluated experimentally using airborne standard polystyrene latex (PSL) particles. In addition, two airborne microorganisms, Adenovirus 40 and Staphylococcus epidermidis, were used to verify the performance of the separator. The separation ratios of each bioaerosol were measured using real-time aerosol measurement instruments and quantitative polymerase chain reaction (qPCR) analysis. The system was composed of two 90° curved microchannels and three outlets for separating the virus, bacteria and larger particles. About 70% of 3 μm particles but almost none of the bioaerosols were separated out at the first outlet. In addition, more than 70% of S. epidermidis and ~70% Adenovirus were separated out at the second and third outlets, respectively. Unwanted particle loss in the system was less than 10%. The results indicated not only good separation of bioaerosols but also the potential of our separator for use in bioaerosol applications.

Microfluidic Platform for Cell Isolation and Manipulation Based on Cell Properties

“…Jimenez et al [ 92 ] demonstrated separation of viable waterborne pathogens like Cryptosporidium parvum. Hong et al [ 93 ] utilized two 90° curved channels to separate viruses, bacteria and larger aerosols into three outlets, thus showing an improvement over traditional bioaerosol sampling methods.…”

High-precision extraction and concentration detection of airborne disease microorganisms based on microfluidic chip

“…There are still significant limitations in terms of detection accuracy and sensitivity, and there are no practical microbial sensors available in the market. 14 Related studies such as the one by Hong constructed a curved channel inertial microfluidic control to achieve the separation of bacteria and viruses of different particle sizes in aerosols, 27 but in general, there are few related studies and lack of data. The above research on particle separation in the gaseous state is mainly based on the inertial principle of the movement of the microenvironment particles, that is, the particles of different masses and particle sizes moving in the microchannel with a certain distance after the airflow, and the motion position is fixed at a certain position, the required particles are then extracted from these locations, which require a sufficiently compact chip structure, but is apt to complicate the structural design.…”

Real-time separation of aerosolized Staphylococcus epidermidis and polystyrene latex particles with similar size distributions

“…Results indicate that the extent of inhibition by dust on PCR varies with the type and amount of dust. Therefore, an additional step, such as centrifugation for inertial particle separation, is required in order to obtain a target microbe before quantitative, accurate identification (e.g., nucleic acid amplification) (Hong et al 2015). Sensors and microchips are increasingly being used to detect target microbe particles (Han et al 2008;Lee et al 2008;Aravind et al 2014;Jing et al 2013).…”