AC electroosmosis micromixing on a lab-on-a-foil electric microfluidic device

The efficient mixing of fluids in lab-on-a-chip devices is very important for many biomedical and biochemical applications. Lab-on-a-foil as a novel concept provides a method for fast prototyping or mass production of microfluidic devices based on thin and flexible film materials. In this work, electroosmosis micromixing is conducted in a lab-on-a-foil microfluidic device. With the electroosmotic flow (EOF), an efficient micromixing is realized inside a microchannel by tooth-shaped planar electrodes. The mixing performance is evaluated based on intensity measurement, and frequency sweeping is used to identify optimal performance. Furthermore, according to local intensity profiles, the EOF pattern is analyzed to provide a deep understanding of the influence of frequency and flow rate. The amplitude of voltage and the number of pairs of electrode teeth are also investigated to find the optimal conditions of the device. To the best of our knowledge, this is the first demonstration of the AC EOF in a lab-on-a-foil electric device and the exploration of the EOF pattern vertically and horizontally in the microchannels. This study provides a method to optimize mixing performance in an EOF-based micromixer. Furthermore, the fabrication method cast the potential for mass production of low-cost flexible electric microfluidic devices.