Simulation and experimental investigation on the circular concentration gradient generator

Abstract

This article introduced a specific design and an effective, low-cost production method of the concentration gradient generator. It can generate different concentration at eight outlets. Deep research on the position of inlet and the flow velocity of inlet were carried to study the effect on generating concentration gradient. The position of the entrance firstly was discussed. Then a variety of different concentration gradient profiles with different flow velocity were got. When the flow velocity of two inlets is 10⁻⁵m/s, the effect of concentration gradient curves is the best. The resulting concentration gradient changes when the flow velocity of the two inlets is out of step. In addition, the construction of the grid is also important in simulation. By comparing the concentration curves with different grid numbers, the grid number of concentration gradient generator is finally set to 5105969. The concentration gradient generators were fabricated using Polymethyl-methacrylate (PMMA) by CO₂ laser machine and thermocompressor. Finally, the feasibility of simulation was clearly verified by a mixing experiment with blue ink and yellow ink. This simple microfluidic device can help the study of high-throughput concentration gradient applications such as cell biology of chemotaxis or hypotaxis.

Graphical Abstract

Keywords:

• Concentration gradient generator
• CO₂ laser
• PMMA substrate

Acknowledgment

We sincerely thank Prof. Chong Liu for his kind guidance.

Additional information

Funding

This work was supported by LiaoNing Revitalization Talents Program (XLYC1907122), Liaoning Natural Science Foundation (2019-MS-169), and Chunhui Plan of Ministry of Education of the People’s Republic of China (2020).