Simple density-based particle separation in a microfluidic chip

Abstract

We investigate the behaviour of a simple microfluidic device designed to separate particles based on density. The device consists of a separation-channel with three inlet and two outlet channels. The particle samples were loaded in the middle of the main channel. The results of separation experiments using model particles provide clear evidence that this approach can be used to achieve good separation of particles of close density populations. Particle separation was found more favourable with low flow rates. Forces exerted on particles were modelled by Stokes' law and found to be consistent with experimental results. One advantage of this microfluidic system is low exposure of the sample to hydrodynamic shear stresses compared with conventional methods. This device may be adopted to precisely handle single cells and easily interface with other tools and separation techniques.

Simple separation of good quality bovine oocytes using a microfluidic device

“…The microfluidic separation device was designed based on a previously fabricated density-based particle separation device 17 . Figure 3 shows the concept of oocyte separation in a microfluidic device.…”

“…4 because the oocytes were sorted according to differences in their sedimentation rate. The oocyte separation device was fabricated by a standard polydimethylsiloxane (PDMS) molding method, same as the previously developed particle separation device 17 . Briefly, two master polymethylmethacrlate (PMMA) molds of the upper plate and bottom plate were fabricated by a micromilling machine.…”

“…This method simplified evaluation of the mechanical characteristics of oocytes using an automated system; however, it lost the advantages of simple and low-cost fabrication of a microfluidic device because it requires a microelectromechanical system device and a control unit. Conversely, we have previously developed a density-based separation technique using a microfluidic device 17 . This method is based on sink-float separation of particles.…”

Modeling of Microdevices for SAW-Based Acoustophoresis — A Study of Boundary Conditions

“…However, during the last three decades, microfluidic devices have proven to be a valuable alternative [ 1 , 7 , 8 ], as they allow for lower sample sizes and decentralized preparations of biological samples, increasing the potential for point-of-care testing. Microfluidic methods for separating particles suspended in a medium include passive methods where particle separation is solely determined by the flow and the size or density of particles [ 2 , 9 , 10 , 11 , 12 ], and active methods where particles migrate due to the application of various external fields each targeting specific properties for particle sorting [ 1 , 3 , 4 , 6 , 13 , 14 , 15 , 16 ]. Acoustophoresis is an active method, where emphasis is on gentle, label-free, precise handling of cells based on their density and compressibility relative to the suspension medium as well as their size [ 17 ].…”

Microfluidics Era in Chemistry Field: A Review

“…A success separation of 20 m polystyrene particles from 3 m particles has been achieved using this technique [17]. By using a similar technique, a simple separation of submillimeter-sized particles reach 90, 90, 85, 65 and 55% degree of separation for 20, 30, 60, 90 and 150 L min -1 flow rate, respectively [18]. On the other hand, a simple separation of bovine oocytes has been performed within seconds, which is remarkable for biochemistry field [19].…”