Abstract
We present a microfluidic device for focusing and separation applications of large particles exploiting inertial migration in curved microchannels. Due to the curvilinear geometry of the microchannel particles experience a combination of inertial lift and Dean drag forces causing a lateral equilibration at a position near the inner wall. Depending on the ratio of lift and Dean drag forces particles with different sizes occupy distinct equilibrium positions resulting in individual particle streams. For testing the principle, a 5 loop spiral microchannel was used. Channel width and spacing between successive loops were fixed to 500μm and the height to 220μm. To evaluate the device for sorting large insect cells, particle focusing and separation was carried out using fluorescently labeled 40μm and 60μm polystyrene beads.
Highlights
Focusing and sorting of micro particles or biological cells in microfluidic systems for analysis applications is a process of great importance [1]
Due to inertial lift forces arising from the parabolic nature of the laminar velocity profile in a Poiseuille flow, suspended particles migrate across the streamlines to an equilibrium position away from the channel centre
Since the ratio of the lift force FL to the Dean drag force FD depends on particle size, particles with different diameter equilibrate at distinct positions resulting in a continuous separation of multi-sized particle mixture
Summary
Focusing and sorting of micro particles or biological cells in microfluidic systems for analysis applications is a process of great importance [1]. Various techniques employing external forces, such as dielectrophoresis, acoustic waves, and optical interference have been used on the microscale [2]. These techniques show integral limitation including modification of particles or cellular properties and reduced sample volumes due to the low operating flow rates [2]. High throughput passive particle separation based on inertial migration in curved microchannels has been described [3]. This method avoids the disadvantages of conventional techniques needing externally applied forces since only fluidic forces and particle size influence the particle separation. We applied a spiral microchannel for focusing and separation of a mixture of large-sized particles with a diameter of 40 μm and 60 μm
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
