Topology optimization design of micromixer based on principle of Tesla valve: An experimental and numerical study

Micromixers are known to be an important part of the integrated microfluidic system, but how to improve its mixing performance at low Reynolds number has always been a difficult problem to be solved. In this study, topology optimization is carried out to reach better mixing performance for micromixers based on the principle of Tesla valve. Firstly, the design model and optimization mathematical model are established for topology optimization problem. Then, the influences of different fluid characteristics are discussed. The optimal results from both the Newtonian fluid and non-Newtonian fluid are obtained by topology optimization method, and the simulation shows that the optimized structure by non-Newtonian fluid has better mixing index than that by Newtonian fluid. Next, different optimization objectives, including maximizing mixing index and maximizing power dissipation ratio are considered. The optimization and simulation results reveal that maximizing the power dissipation ratio can get excellent mixing efficiency. Finally, periodic micromixer is manufactured and the experiment is implemented. Viscosity matching experiment is conducted to obtain expected synthetic blood as non-Newtonian fluid reagent. The liquid mixing distribution and pressure drop of periodic micromixer by experiment indicate the feasibility of the proposed design method and the accuracy of the simulation.