Enhancement of Microfluidic Cell Separation Using Cross-Flow Filters with Hydrodynamic Focusing
Date Issued
2015
Date
2015
Author(s)
Chiu, Yun-Yen
Abstract
A microfluidic chip is proposed to separate particles using cross-flow filtration enhanced with hydrodynamic focusing. By exploiting a buffer flow from side, the particles in the sample flow are pushed on one side of the microchannels, while a larger pressure gradient in the filters is obtained to enhance separation efficiency. Our proposed mechanism has the buffer flow to create a moving virtual boundary for the sample flow to actively push all the particles to reach the filters for separation. This filtration device only requires soft lithograph fabrication to create microchannels and a novel pressurized bonding technique to make high-aspect-ratio (HAR) filtration structures. A mixture of polystyrene particles with 2.7 μm and 10.6 μm diameters are successfully separated. 96.2 ± 2.8% of the large particle are recovered with a purity of 97.9 ± 0.5%, while 97.5 ± 0.4% of the small particle are depleted with a purity of 99.2 ± 0.4% at a throughput of 10 μl/min. The experiment is also conducted with the sample solutions of spiked PC3 cells in whole blood, whole blood sample and cord blood sample. Our device offered a label-free and high separation efficiency technique with simple fabrication and integrable possibility with other components as a promising tool for continuous cell filtration and analysis.
Subjects
fetal cells
prenatal diagnosis
microfluidics
cross-flow
cells separation
Type
thesis