A proportion of under the light stress can effectively conduct astaxanthin biosynthesis, leading to the increase in cell size. Although the size is a critical indicator for identifying the astaxanthin-rich cells, the cut-off size to be separated varies from sample to sample. Here, we report an ultrastretchable, straight elasto-inertial microchannel with tunable separation threshold to continuously separate the light-induced cells by size. The symmetrical sheath flows confine the particles to the channel sidewalls, and large particles can cross the interface of viscoelastic fluids to the equilibrium position at the channel centerline. By stretching the microfluidic chip, the medium-sized particles can gradually migrate to the channel centerline in the narrower and longer channel, bringing the tunable separation threshold. Results show that the separation performance of the ultrastretchable microfluidic device is affected by total flow rate, flow rate ratio of sheath to sample, polyethylene oxide (PEO) solution configuration. Lastly, size-tunable separation of light-induced cells is demonstrated. To the best of our knowledge, this is the first report on cell migration in co-flow configurations in the ultra-stretchable microfluidics. Separation of is not only a relevant end application in harvesting the astaxanthin-rich species, but the separated populations of highly productive microalgal cells will open a venue for cellular directed evolution.

中文翻译：

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使用超拉伸鞘流辅助弹惯性微通道连续可调分离光诱导雨生红球藻


一部分在光胁迫下可以有效地进行虾青素生物合成，导致细胞体积增大。尽管大小是识别富含虾青素的细胞的关键指标，但要分离的截止大小因样品而异。在这里，我们报告了一种超可拉伸的直弹性惯性微通道，其分离阈值可调，可根据尺寸连续分离光诱导细胞。对称的鞘流将颗粒限制在通道侧壁上，大颗粒可以穿过粘弹性流体界面到达通道中心线的平衡位置。通过拉伸微流控芯片，中等尺寸的颗粒可以在较窄和较长的通道中逐渐迁移到通道中心线，带来可调的分离阈值。结果表明，超拉伸微流控装置的分离性能受总流量、鞘管与样品的流量比、聚环氧乙烷（PEO）溶液配置的影响。最后，证明了光诱导细胞的尺寸可调分离。据我们所知，这是第一份关于超可拉伸微流体中同流配置中的细胞迁移的报告。分离不仅是收获富含虾青素物种的相关最终应用，而且分离的高产微藻细胞群体将为细胞定向进化开辟场所。