The dielectrophoresis-based chaining and screening of flagellate algae using a serrated bipolar electrode array

Flagellate algae can rapidly produce dissolved oxygen through photosynthesis with autonomous flagellar motility, making them advantageous for drug delivery and chronic wound treatment. Dielectrophoresis (DEP) has been recognized as an effective tool for the screening of cells, but investigations into the chaining and screening of flagellate algae are not so advanced. Based on this, we developed a microfluidic chip with serrated bipolar electrodes for the DEP-based chaining and screening of flagellate algae. First, a solid-liquid coupling simulation model was established to investigate the chaining and screening of flagellate algae under positive and negative DEP force by tuning the electric field distributions. Second, we designed and fabricated a microfluidic chip with serrated bipolar electrodes, and established an experimental platform to explore the chaining and screening of flagellate algae. Third, the chaining process of E. gracilis was investigated, the method was shown to be non-destructive, and the effects of voltage amplitude and flow velocity on the chaining process and capture efficiency were studied. Finally, we used this microfluidic chip to screen E. gracilis and H. pluvialis; we studied the duration of separation and explored the effects of voltage amplitude, frequency, and flow rate on the screening efficiency. This method can realize the screening of flagellate algae for drug delivery and chronic wound treatment via microalgae-based microrobots with the advantages of being sheathless and having strong adaptability.