Simulation of multi-point mixing concentration gradient generator

Abstract

This paper proposes a new concentration gradient generator based on the principle and flow characteristics of solution mixing in the microchannel. This concentration gradient generator works with oscillating bubbles in the microchannel, which are excited with bulk acoustic wave. The oscillating bubbles are used to mix the solution in the microchannel. The volume of each bubble is controllable individually and the number of bubbles partaken mixing is adjustable. Therefore, the mixing position of the solution and the concentration gradient in the microchannel are adjustable. Therefore, the new concentration gradient generator has the advantages of fast response and high flexibility. Simulation software COMSOL 5.5 was used to simulate the influence of the inlet flow rate, the bubble amplitude, and the number of bubbles on the mixing result. The simulation result shows that the inlet flow rate and the bubble amplitude affect the mixing width of the solution in the microchannel. The simulation result also shows that the concentration distribution with different gradient can be generated by adjusting the number of bubbles located in the solution microchannel. The simulation has an important reference for the design of the concentration gradient generator.