Fig. 6: Separation efficiency of microalgae in spiral contraction-expansion double-sided coupled channels.

a Depicts the structural framework and a schematic diagram of the spiral contraction-expansion double-sided coupled microchannel, showcasing its innovative design for microalgae separation. b Presents the separation of mixed microalgae species through the channel at flow rates of 150 µL/min and 200 µL/min, demonstrating the channel’s capability to discriminate between different microalgae species based on their size and inertial properties. c Displays the separation outcomes at the channel outlets for mixed microalgae, measured at the specified flow rates, with a focus on the efficiency and purity of the separation process. d, e Quantify the purity levels of C. vulgaris and H. pluvialis, respectively, in the collected solutions from each outlet at a flow rate of 200 µL/min, indicating the channel’s effectiveness in achieving high purity separations. f, g Illustrate the 7-day cultivation results of the separated microalgae at Outlet 1 and Outlet 2 of the spiral contraction-expansion double-sided coupled microchannel, respectively, confirming the vitality and growth potential of the separated microalgae species post-separation