Microfluidic particle sorting utilizing inertial lift force

Abstract

A simple passive microfluidic device that continuously separates microparticles is presented. Its development is motivated by the need for specific size micro perfluorocarbon (PFC) droplets to be used for a novel gas embolotherapy method. The device consists of a rectangular channel in which inertial lift forces are utilized to separate particles in lateral distance. At the entrance of the channel, particles are introduced at the center by focusing the flow from a center channel with flow from two side channels. Downstream, large particles will occupy a lateral equilibrium position in shorter axial distance than small particles. At the exit of the channel, flow containing large particles is separated from flow containing small particles. It is shown that 10.2-μm diameter microspheres can be separated from 3.0-μm diameter microspheres with a separation efficiency of 69-78% and a throughput in the order of 2 ·10⁴ particles per minute. Computational Fluid Dynamics (CFD) calculations were done to calculate flow fields and verify theoretical particle trajectories. Theory underlying this research shows that higher separation efficiencies for very specific diameter cut-off are possible. This microfluidic channel design has a simple structure and can operate without external forces which makes it feasible for lab-on-a-chip (LOC) applications.

Microfluidic sorting of microtissues

“…Microfluidic platforms have been utilized for several years to improve efficiency, accessibility, and flexibility of systems designed to purify small particles [15][16][17][18][19] and have been utilized more recently to purify large particles based on particle size. 20,21 In particular, a microfluidic 1 mm glass capillary sorting mechanism was developed using diode laser bars to optically trap or deflect particles up to 200 lm in diameter.…”

Analysis of rotational flow generated by circular motion of an end effector for 3D micromanipulation

“…To generate a precise motion at high speed for formulating model clearly, we tried to suppress vibration less than 1 μm. We tested several lengths of end effector (14,16,18,20, and 22 mm) and finally chose the length at 16 mm because the vibration is lower than 1 μm. As a result, we obtained an end-effector workspace of approximately 80 μm in X-and Z-directions and 10 μm in Y-direction.…”

“…Chung et al [17] generated a stream by oscillating a bubble for 3D manipulation of microobjects. Nieuwstadt et al [18] applied inertial lift force for sorting particles. The methods using field forces, including acoustic waves, the dielectrophoretic method, stream by bubble, and lift force, can manipulate multiple objects at the same time, but have difficulty in manipulating objects selectively.…”

Development of a multi frequency impedance measurement system for use in MEMS flow cytometers

“…There are also issues due to the narrowing of the channel that has detrimental effects in terms of changes in pressure and flow. Blockage and cell damage can occur at the constriction (Nieuwstadt 2011). The ability to discern individual cells and provide a reliable count is directly related to the flow rate, relative cell density, length and diameter of the channel.…”