Design and optimization of Tesla micromixer with asymmetrical arrangement for efficient mixing in microfluidic chip

Abstract

As a crucial pre-treatment part of the Micro Total Analysis Systems, micromixers are widely used in bioengineering, biochemical analysis, chemical detection and other fields. In this study, a novel Tesla micromixer (TSM) with an asymmetrical arrangement is designed. The asymmetrically arranged Tesla units generate significant vortices and localized mixing effects, enhancing the overall mixing efficiency. The effects of obstacle arrangement, geometry, and size on its mixing performance of the micromixer are investigated. The results indicate that fluids of varying concentrations are continuously compressed and collided along the TSM's fluid interface, improving the transverse diffusion effect during the mixing process. At Reynolds numbers (Re) between 30 and 100, the TSM achieves a mixing efficiency exceeding 0.7. Compared to other asymmetrically arranged Tesla micromixers, the TSM features a simpler structure and experiences less pressure drop during the mixing process. The two-way arrangement of obstacles is more effective at inducing secondary vortices and enhancing fluid mixing than the one-way arrangement, with triangular obstacles outperforming rhombic and cylindrical ones in promoting fluid mixing. With a bidirectional layout, triangular shape, and obstacle size of D=150 µm, the TSM achieves a mixing index between 0.85 and 0.99 within the Re range of 20 to 100. This research offers valuable insights into the design and optimization of the Tesla micromixer, providing essential guidance for fluid mixing in microfluidic systems.