Particle Separation in Microfluidic Devices 3/4 SPLITT Fractionation and Microfluidics

Abstract

In recent years, microfluidic devices have been increasingly used to separate particles such as colloids, macromolecules, cells, beads and droplets. Miniaturisation often introduces new functionalities and paradigms that are not possible at conventional macroscopic scales. In this paper, split-flow-thin fractionation techniques for particle separation are reviewed and the underlying physics of particle migration is discussed. The potential of these particle separation techniques in the design of integrated microfluidic systems is described. We then illustrate how numerical simulation can provide an increased understanding of the fluid-particle motion. The advantages of numerical simulation for rational design and operation of microfluidic devices are highlighted through two practical examples involving an ultrasonic cell washing system and a quadrupole magnetic flow sorter.

Shrink-film microfluidic education modules: Complete devices within minutes

“…[48][49][50][51] A gradient can easily be generated with the use of the fluorophore fluorescein or food coloring. Once the students generate a gradient using fluorescein ͑or food coloring͒ and de-ionized ͑DI͒ water, they will learn image processing software such as with the openware Module 3 challenges the more advanced college students to develop a gradient using the same gradient generator as module 2 and perform a biomolecular assay on-chip.…”

“…In addition, the concept of dimensionless numbers such as Reynolds number and Stokes number, which plays an important role in the characterization of fluid flow, can be incorporated into the teaching module through simple flow velocity measurements with known device dimensions. 45,51 Together, these modules will teach students fabrication techniques, flow patterns in microfluidics, relevant calculations for microfluidics, and data processing and analysis. Most importantly, these educational modules offer a hands-on experience and cover the breadth of important foundations in microfluidics and applications in real-world POC diagnostics.…”

“…H-filters separate particles based on the principle of the nonmixing property of laminar flow along with the relative diffusivities of different size molecules. 47,48,51,[55][56][57] To demonstrate separation, crucial in the miniaturization and adaptation of microfluidics to LOC technology and POC diagnostics, fluorescent microbeads of 0.5 and 25 m diameter were mixed with water and introduced to one inlet of the device. Next, pure DI water was introduced into the other inlet, and a constant flowrate of 30 L / h was applied to both inlets.…”

Separation Units

“…The use of microfluidic devices for split flow FFF (referred to as SPLITT) was covered by Fuh [86] and more recently reviewed by Zhang et al [87]. Separations at split flow outlets are described by Fuh for centrifugal, magnetic, and electrical fields.…”

Dynamics of Superparamagnetic and Ferromagnetic Nano-Objects in Continuous-Flow Microfluidic Devices

“…Manipulation and capture of magnetic carriers in flow conditions require a careful design of the magnetic field gradients and appropriate flow conditions for the magnetic carriers. Numerical simulations aimed to find accurate solutions for the differential equations of motion of the magnetic carriers subjected to both magnetic field gradient and flow conditions can provide an increased understanding and consequently a better design of these devices [7].…”