Fluid Mixing Using Induced Charge Electro-Osmotic Transverse Flow Actuated by Asymmetrical Driving Electrode Sequence

Microfluid mixing is an essential process in chemical analysis, drug test, and nanoparticle synthesis. Induced charge electro-osmosis (ICEO) has good capability in microfluid mixing for its reconfigurable vortex profile. We found experimentally ICEO transverse flow induced by the asymmetrical driving electrode has a good performance in disturbing the interface of two fluids. Encouraged by these aspects, we proposed a micromixer using ICEO transverse flows actuated by the asymmetrical driving electrode sequence to mix microfluids. We established a simulation model to investigate the evolution of the interface and demonstrate the work principle of this method. Moreover, we numerically explored the effects of device structure, and electrolyte characteristics on the capability of micromixer. Finally, we validated this method experimentally, and studied the effects of voltage intensity, frequency and flow rate on the mixing capability, obtaining mixing efficiency exceeding 94%. This method is a potential alternative in various microfluidic and lab-on-a-chip applications.