Focusing of sub-micrometer particles and bacteria enabled by two-dimensional acoustophoresis.
Författare
Summary, in English
Handling of sub-micrometer bioparticles such as bacteria are becoming increasingly important in the biomedical field and in environmental and food analysis. As a result, there is an increased need for less labor-intensive and time-consuming handling methods. Here, an acoustophoresis-based microfluidic chip that uses ultrasound to focus sub-micrometer particles and bacteria, is presented. The ability to focus sub-micrometer bioparticles in a standing one-dimensional acoustic wave is generally limited by the acoustic-streaming-induced drag force, which becomes increasingly significant the smaller the particles are. By using two-dimensional acoustic focusing, i.e. focusing of the sub-micrometer particles both horizontally and vertically in the cross section of a microchannel, the acoustic streaming velocity field can be altered to allow focusing. Here, the focusability of E. coli and polystyrene particles as small as 0.5 μm in diameter in microchannels of square or rectangular cross sections, is demonstrated. Numerical analysis was used to determine generic transverse particle trajectories in the channels, which revealed spiral-shaped trajectories of the sub-micrometer particles towards the center of the microchannel; this was also confirmed by experimental observations. The ability to focus and enrich bacteria and other sub-micrometer bioparticles using acoustophoresis opens the research field to new microbiological applications.
Avdelning/ar
Publiceringsår
2014
Språk
Engelska
Sidor
2791-2799
Publikation/Tidskrift/Serie
Lab on a Chip
Volym
14
Issue
15
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Royal Society of Chemistry
Ämne
- Medical Engineering
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1473-0189