Document Type : Research

Author

• Parisa Mahmoudi

Department of Electrical Engineering, Payame Noor University (PNU), Tehran, Iran

Abstract

Effective mixing of samples is a critical requirement in many biochemical processes. However, achieving fast and homogeneous mixing in microfluidic channels presents significant challenges due to the low Reynolds number characteristic of microscale fluid flows. This study introduces an active micromixer with a non-symmetric lateral geometry that facilitates the application of electroosmotic flow, particularly near the inlet and, most notably, at the outlet of the mixing chamber. In this proposed configuration, input fluids are more rapidly and precisely subjected to efficient mixing, under very low applied voltages. As a result, a higher quality of fluid mixture is achieved throughout the mixing chamber, driven by vortices generated through electroosmotic stimulation as well as the sharp edges within the chamber. Additionally, the mixing quality is further modified by the electric field at the outlet of the mixing chamber. This performance reduces the effective mixing time, minimizes the required voltage amplitude, improves the Mixing Index, and ensures consistent and stable operation over time. According to the finite element simulation results, at an applied voltage of 0.1 volts, the mixing time is less than 2 seconds, and the Mixing Index is 0.98. Consequently, this design is highly safe and efficient for lab-on-a-chip microfluidic applications, where the integrity of the samples within the mixers must remain unchanged.

Keywords

• Micromixer
• Electroosmotic
• Electrode
• Concentration
• Mixing Index