Efficient separation of small microparticles at high flowrates using spiral channels: Application to waterborne pathogens

Melanie Jimenez,Brian Miller,Helen L Bridle

doi:10.1016/j.ces.2015.08.042

Melanie Jimenez, Brian Miller + Show 1 more

Open Access

https://doi.org/10.1016/j.ces.2015.08.042

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Abstract

Detecting waterborne pathogens is a challenging task because of their low concentration in water and their wide diversity. In order to ease this detection process, the potential of microfluidics is investigated in this paper. Spiral channels are designed for separating particles, in a single device and without any external forces or additional buffer, depending on their size at high flowrates. This paper focuses first on the impact of the channel length, flowrate, particle concentration and size on the separation efficiency of polystyrene beads of relevant sizes (4–7μm). The system is then tested with viable and non-viable pathogens (Cryptosporidium parvum) with an average size around 4–5μm.

Highlights

Detecting waterborne pathogens is a challenging task because of their low concentration in water and their wide diversity
Studies have proposed a direct miniaturization of the final stages of the current process for microfluidic filtration and immuno-magneticseparation clogging issues and the specificity to single pathogens are still limiting their practical use by water companies
Inertial focusing in spiral channels was investigated for the first time for separating and concentrating waterborne pathogens such Cryptosporidium

Summary

Introduction

Detecting waterborne pathogens is a challenging task because of their low concentration in water and their wide diversity. Studies have proposed a direct miniaturization of the final stages of the current process for microfluidic filtration and immuno-magneticseparation clogging issues and the specificity to single pathogens are still limiting their practical use by water companies Dielectrophoresis is another technique proposed in the literature for concentrating and separating Cryptosporidium but the working flowrates are usually small, while hundreds of millimetres need to be analysed after filtration. As recently reviewed (McGrath et al, 2014), DLD can perform efficient separation in complex biological media such as blood This technique has been successfully scaled up for separating ‘angry pathogens’ with LEGO s for outreach activities (Jimenez and Bridle, 2015), the presence of posts in the channel makes DLD devices prone to clogging and potentially not suitable for routine procedures. The interested reader is invited to consult the recent review of Amini et al (2014)

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