Design and simulation of sample pinching utilizing microelectrodes in capillary electrophoresis microchips

Abstract

The paper proposed novel designs to pinch the transverse diffusion of the sample in the injection mode using microelectrodes to generate the potential difference at the channel intersection in the capillary electrophoresis (CE) microchip. A pair of microelectrodes was used to conduct the injection channel and the separation channel, which directly provided the potential to pinch the sample without using a power supply. These new designs of the CE microchip simplify the electric circuitry and improve performance. Simulations were performed using the CFD-ACE[trade mark sign] software. The mechanisms of diffusion and electrophoresis were employed in the numerical simulation. The injection and separation processes of the sample were simulated and the parameters of the present design were investigated numerically.

Model and verification of electrokinetic flow and transport in a micro-electrophoresis device

“…ref. 27). Pinching uses the arrangement of four active electrodes during the injection process, with the aim of preventing sample dispersion in the intersection.…”

Towards numerical prototyping of labs-on-chip: modeling for integrated microfluidic devices

“…In another early study, Bianchi et al (2000) performed FE-based simulations of electrokinetic flow at a T-junction. Building on those initial studies, Fu et al (2002aFu et al ( , b, 2003; Lin et al (2002Lin et al ( , 2004a, Ren et al (2002Ren et al ( , 2003 and Jin and Luo (2003) developed advanced numerical simulators and used them to develop a variety of novel and complex pinching and dispensing techniques. Of particular interest are the works of Tang et al (2002) who modeled and developed an electrokinetic technique for composition modulation in microfluidic systems involving the high-frequency oscillation of the inlet voltages and Chmela et al (2002) who took a different approach and used fluent-based simulations to design and characterize a pressure-driven flow based sample injection technique.…”

Modeling of cell sorting and rare cell capture with microfabricated biodevices

“…Beyond the typical plug shape of EOF, one of the most important advantages of electroosmotic focusing techniques is the lack of moving parts in the chip layout, reducing the risk of damage, while also decreasing cost. Kohlheyer et al [37], Lin et al [38], and Li et al [39] Q6 used CFD simulations to analyze the distribution of the electric field inside a microfluidic chip. A recent publication [40] is especially interesting from the viewpoint of modeling and simulation of this phenomena.…”