Novel Bifurcation Design for Centrifugal Microfluidic Platform With Wide Range Rotational Speed

Abstract

A compact disk-based enzyme linked immunosorbent assay (CD-ELISA) is used in a wide range of applications including cancer and human immunodeficiency virus testing, drug screening, and micro-organism identification. Bifurcation design is the most important structure for microfluidic channels in CD-ELISA. In this study, a bifurcation design feasible for mass production and suitable for applications over a wide range of rotational speeds is proposed. Simulations based on two-phase flow theories along with incompressible flow theories were used in this study to confirm the feasibility of the novel design. The factors that influenced the bifurcation ratio for microfluidic channels in CD-ELISA were also investigated. The geometric length for bifurcation, opening angles, and the bifurcation shape in the middle section were varied to investigate the effects of each factor on the bifurcation ratio. From the experimental results, the factors with the greatest influence on the bifurcation ratio were the geometry of the end face of the partitioning plate and the distance from the opening end. These factors can be used as controlling factors for the design of microfluidic channels.

Mathematical modeling and computational analysis of centrifugal microfluidic platforms: a review

“…Lin et al (2010), for example, used the phase-field method to study bifurcation in LOD devices. 120 This geometry, which is shown in Fig. 20(A), is of particular use in CD-based enzymelinked immunosorbent assays (CD-ELISA).…”

“…One of these geometric parameters, as the ratio of two flows versus S is shown for three different partition plate angles. 120 (B) The geometry and initial condition of droplets A and B considered by Liu et al 44 Reprinted with the permission of AIP Publishing. (C) Collision process of the droplets in an LOD device.…”

Parametric analysis of a novel semi-circular microfluidic CD-ELISA valve

“…The parameters used during simulation are listed in Table 1. The width of the microfluidic channel is selected to be 300 micrometers, identical to previous experiments from earlier publications [15,3]. Before we investigate the new valve structure, we first perform analysis on rotational speed for fish-bone valve structures.…”

“…Two-phase flow theory is necessary because there are large differences between air density and liquid density, and the numeric calculations do not easily converge. In the past, some studies have successfully used two-phase flow theory and incompressible theory in bifurcation design for microfluidic channels [ 15 ]. For the same structure, calculated results using both theories have minimal or no difference.…”

“…The size of the cross-section affects the flow speed. Compared with the bifurcation design [ 15 ], the effect of Coriolis forces is small, and the changes on the cross section are not dramatic; therefore the changes in flow speed are very smooth.…”