Portable Dielectrophoresis Microfluidic Chip Integrated With Microscopic Platform for Water Blooms Monitoring

Microalgae concentrations have been studied as an important factor to reflect water qualities. High concentration of microalgae should cause water eutrophication then cause environment pollution. However, conventional methods to monitor algal concentration in source water whose use is hampered by high-cost, complicated operation and the need of a centralized laboratory for practical samples' analysis. In order to overcome these constraints, here in this work, we developed a portable and real-time monitoring platform which consists of a microfluidic chip for algae enrichment, a portable microscopic imaging system integrated with a commercial smartphone. The chip is designed and fabricated with a multi-layer electrode structure to trap algaes via alternating current electrokinetics (ACEK) effect. A temperature dependent fully coupled numerical model is presented to calculate the ACEK flow, showing satisfied trapping performance by adjusting the applied voltage and frequency. Moreover, preliminary experiments are performed in our chip using freshwater samples, in which algae trapping behavior is visually observed and recorded by a self-designed portable microscope. Then the trapping performance of this system can be semi-quantitatively figured out by image processing. This lab-on-a-chip system shows high potential in concentrating bio-particles and developing a portable, integrated and automated system for monitoring the quality of water resources in nature. [2020-0381]