Effects of embedded sub‐micron pillar arrays in microfluidic channels on large DNA electrophoresis

Abstract

A study of the influences of embedding artificial structures in a microfluidic device for CE with a free buffer solution is presented. Compared with conventional slab-gel electrophoresis, three major additional effects on the overall system performance are identified when sub-micron pillar arrays are integrated into a standard CE microsystem. Since DNA molecules have to migrate in-between and interact with the pillars, pillar geometry is first demonstrated to have a direct impact on the DNA motion pattern. Electric field re-distribution is another inevitable outcome when features of sub-micron dimensions are placed inside a microchannel. This effect is verified by a numerical simulation tool. Furthermore, the integration of the closely packed sub-micron structures dramatically increases the surface to volume ratios in the microfluidic device and therefore generates a large EOF. The consequence of these additional influences implies a complexity in the measured DNA velocity and indicates that careful considerations have to be taken when these devices are used for DNA electrokinetics study or electrophoresis theory re-examination.

Beyond Gel Electrophoresis: Microfluidic Separations, Fluorescence Burst Analysis, and DNA Stretching

“…Arrays created by conventional photolithography techniques, which can pattern micron sized posts 37,158,312,324,325,348,349 as well as sub-micron posts, 160,162,341,350 are capable of producing centimeter-long separation channels. Moreover, projection lithography permits access to sub-micron sized posts while maintaining a reasonably large area pattern.…”

Electrophoretic collision of a DNA molecule with a small elliptical obstacle

“…Moreover, the Brownian ratchet obstacles are rotated with respect to the net electric field [15][16][17][18]. Denser and smaller elliptical obstacles have also been incorporated into the standard obstacle course array [19]. In general, small-scale ''rectangular'' obstacles often feature rounded corners and can be approximated as ellipses.…”

Hydrodynamics of Diamond-Shaped Gradient Nanopillar Arrays for Effective DNA Translocation into Nanochannels

“…29,30 To catalyze the crossing of this entropic barrier, it is critical to pre-stretch the DNA molecules. This can be achieved by nanopatterning features such as nanochannels 31,32 or nanopillars [33][34][35] . For the best performance, such pre-stretching features need to be patterned over a large area with a dimensional gradient from the micrometer to the nanometer regime and ultimately interface with the critical nanochannel/pore entrance.…”