Du Jiayou, Li Long, Zhuo Qiuyi, Wang Ruijin, Zhu Zefei
School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
Micromachines (Basel). 2020 May 31;11(6):566. doi: 10.3390/mi11060566.
The sizes of most prokaryotic cells are several microns. It is very difficult to separate cells with similar sizes. A sorter with a contraction-expansion microchannel and applied magnetic field is designed to sort microparticles with diameters of 3, 4 and 5 microns. To evaluate the sorting efficiency of the designed sorter, numerical simulations for calculating the distributions of microparticles with similar sizes were carried out for various magnetic fields, inlet velocities, sheath flow ratios and structural parameters. The numerical results indicate that micro-particles with diameters of 3, 4 and 5 microns can be sorted efficiently in such a sorter within appropriate parameters. Furthermore, it is shown that a bigger particle size and more powerful magnetic field can result in a greater lateral migration of microparticles. The sorting efficiency of microparticles promotes a lower inlet velocity and greater sheath flow ratios. A smaller contraction-expansion ratio can induce a greater space between particle-bands. Finally, the micro particle image velocity (micro-PIV) experiments were conducted to obtain the bandwidths and spaces between particle-bands. The comparisons between the numerical and experimental results show a good agreement and make the validity of the numerical results certain.
大多数原核细胞的大小为几微米。分离大小相似的细胞非常困难。设计了一种带有收缩-扩张微通道并施加磁场的分选器，用于分选直径为3、4和5微米的微粒。为了评估所设计分选器的分选效率，针对各种磁场、入口速度、鞘流比和结构参数，进行了计算大小相似微粒分布的数值模拟。数值结果表明，在适当的参数范围内，直径为3、4和5微米的微粒可以在这种分选器中高效分选。此外，结果表明，更大的粒径和更强的磁场会导致微粒更大的横向迁移。微粒的分选效率随着较低的入口速度和更大的鞘流比而提高。较小的收缩-扩张比会导致粒子带之间有更大的间距。最后，进行了微粒图像测速（micro-PIV）实验以获得粒子带之间的带宽和间距。数值结果与实验结果的比较显示出良好的一致性，并确定了数值结果的有效性。
