Numerical simulation and parameter optimization of micromixer device using fuzzy logic technique

Abstract

The objective of this study is the design, simulation, and performance optimization of a micromixer device using the three input parameters of device structure, flow rate and diffusion coefficient of gold nanoparticles while the output parameters are concentration, velocity, pressure and time domain analysis. Each input parameter in the microfluidic chip influences the system output. The data were gathered through extensive study in order to optimize the diffusion control. The fuzzy logic approach is used to optimize the performance of the device with respect to the input parameters. In this study, we have chosen three different flow rates of 1, 5, and 10 μL min^-1, three different diffusion coefficient values of low, average and high diffusivity gold nanofluids (15.3 e^-12, 15.3 e^-11, 15.3 e^-10 m² s^-1) which are used in three different shapes of micromixer device, Y-shaped straight channel micromixer, herringbone-shaped micromixer, and herringbone shape with obstacles micromixer, and we measured the output performance, such as mixing efficiency, pressure drop, concentration across the microchannel and time domain. The data were obtained by fuzzy logic analysis and it was found that the herringbone shape with obstacles micromixer shows 100% mixing efficiency within a short duration of 5000 μm, and complete mixing was achieved within 10 seconds with a low pressure drop of 128 Pa.

Fig. 1. Y-shaped straight channel micromixer.

Fig. 2. Y-shaped herringbone serpentine channel micromixer.

Fig. 3. Y-shaped herringbone serpentine channel micromixer with obstacles.

Fig. 4. Simulated result of Y-shaped straight channel micromixer.

Fig. 5. Simulated result of Y-shaped herringbone serpentine channel micromixer.

Fig. 6. Simulated result of Y-shaped herringbone serpentine channel micromixer with obstacles: (a) concentration field and (b) streamline distribution at 5000 μm.

Fig. 7. Fuzzy logic model of the micromixer.

Fig. 8. Velocity across the Y-shaped straight channel micromixer.

Fig. 9. Velocity across the Y-shaped herringbone serpentine channel micromixer.

Fig. 10. Velocity across the Y-shaped herringbone serpentine channel micromixer with obstacles.

Fig. 11. Concentration across the Y-shaped straight channel micromixer at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 12. Concentration across the Y-shaped straight channel micromixer at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹¹ m² s⁻¹.

Fig. 13. Concentration across the Y-shaped straight channel micromixer at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹² m² s⁻¹.

Fig. 14. Concentration across the Y-shaped herringbone serpentine channel micromixer at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 15. Concentration across the Y-shaped herringbone serpentine channel micromixer at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹¹ m² s⁻¹.

Fig. 16. Concentration across the Y-shaped herringbone serpentine channel micromixer at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹² m² s⁻¹.

Fig. 17. Concentration across the Y-shaped herringbone serpentine channel micromixer with obstacles at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 18. Concentration across the Y-shaped herringbone serpentine channel micromixer with obstacles at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹¹ m² s⁻¹.

Fig. 19. Concentration across the Y-shaped herringbone serpentine channel micromixer with obstacles at 1 μL min⁻¹ (A), 5 μL min⁻¹ (B), and 10 μL min⁻¹ (C) with a diffusion co-efficient of 15.3 × 10⁻¹² m² s⁻¹.

Fig. 20. Mixing efficiency across the micromixer devices at 1 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 21. Mixing efficiency across the micromixer devices at 1 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹¹ m² s⁻¹.

Fig. 22. Mixing efficiency across the micromixer devices at 1 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹² m² s⁻¹.

Fig. 23. Mixing efficiency across the micromixer devices at 5 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 24. Mixing efficiency across the micromixer devices at 5 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹¹ m² s⁻¹.

Fig. 25. Mixing efficiency across the micromixer devices at 5 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹² m² s⁻¹.

Fig. 26. Mixing efficiency across the micromixer devices at 10 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 27. Mixing efficiency across the micromixer devices at 10 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹¹ m² s⁻¹.

Fig. 28. Mixing efficiency across the micromixer devices at 10 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹² m² s⁻¹.

Fig. 29. Pressure drops vs. flow rates in the micromixer devices.

Fig. 30. The mesh used for geometry.

Fig. 31. Time domain study of Y-shaped straight channel micromixer at 1 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 32. Time domain study of Y-shaped herringbone serpentine channel micromixer at 1 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.

Fig. 33. Time domain study of Y-shaped herringbone serpentine channel micromixer with obstacles at 1 μL min⁻¹ with a diffusion co-efficient of 15.3 × 10⁻¹⁰ m² s⁻¹.