Fig. 7: Microalgae separation in spiral contraction-expansion interleaved coupled channels.

a Depicts the structural composition and a schematic diagram of the spiral contraction-expansion interleaved coupled channel, outlining its innovative design for microalgae separation. b Demonstrates the separation effects of mixed microalgae species within the channel at flow rates of 150 µL/min and 200 µL/min, highlighting the channel’s efficiency in distinguishing between different microalgae under varying flow conditions. c Presents the separation outcomes at the channel outlets for mixed microalgae, measured at 150 µL/min and 200 µL/min flow rates, to assess the channel’s performance in fractionating microalgae species. d and e Quantify the purity of C. vulgaris and H. pluvialis, respectively, in the collected solutions from each outlet at a flow rate of 200 µL/min, indicating the precision of species separation achieved by the channel. f and g Show the 7-day cultivation results of the separated microalgae at Outlet 1 and Outlet 2 of the spiral contraction-expansion interleaved channel, respectively, validating the post-separation viability and growth of the isolated microalgae species