High-throughput separation of microalgae on a runway-shaped channel with ordered semicircular micro-obstacles

Microalgae serve as a valuable biological resource in many industrial applications. Thus, it is essential to obtain a high-efficiency separation technique for microalgae precisely. In this study, a runway-shaped microchannel with ordered semicircular micro-obstacles was introduced to conduct the separation of microalgae with different sizes. The runway-shaped microchannel combined the spiral characteristics with a series of semicircular micro-obstacles to realize the advantage of a sheathless configuration, high-throughput, and low aspect ratio advantages. These micro-obstacles improved the performance of particle focusing, which can promote the microalga separation effectively. These simulated results demonstrated that the runway-shaped channel with ordered semicircular micro-obstacles could form the evident distribution of local Dean vortices to separate particles with different size and density. When the flow rate is considered 4mL/min, the experiment indicated that the microchannel could separate the Chlorella vulgaris and Haematococcus pluvialis in 94.6% and 81.5% purity, respectively. The microchannel with the high throughput and separation efficiency is competent to carry out the task of microalga screening and artificial cultivation.