AUTHOR=Wei Yaming , Zou Jianfeng , Zhao Ziting , Sun Jiaqi TITLE=Enhancing Micro-Droplet Mixing in Microfluidic Systems Via Electrowetting-Induced Parametric Oscillations JOURNAL=Aerospace Research Communications VOLUME=2 YEAR=2025 URL=https://www.frontierspartnerships.org/journals/aerospace-research-communications/articles/10.3389/arc.2024.14205 DOI=10.3389/arc.2024.14205 ISSN=2813-6209 ABSTRACT=

In the context of space exploration, electrowetting-on-dielectric (EWOD) microfluidic systems hold substantial promise for enhancing in-situ analysis and experimentation, particularly given its potential for precise control of fluid dynamics in the microgravity environment. This study investigates the effects of electrowetting-induced parametric oscillations on mixing efficiency within coalesced micro-droplets in EWOD microfluidic devices using numerical simulations. The mechanism by which parametric oscillation affects the mixing process of micro-droplets in EWOD devices is unraveled, which is previously uninverstigated in the literature to the best of our knowledge. The simulations reveal that parametric oscillations significantly increase vorticity magnitude and shear rate around the droplet interface, leading to improved mixing compared to free oscillation. Notably, the study identifies fluctuations in the mixing index associated with the oscillation-induced shape changes of the droplets. These findings underscore the potential of parametric oscillation as a strategy for optimizing mixing in EWOD systems, with implications for the design of more efficient microfluidic devices.