用于卵母细胞保护剂添加过程的微混合器优化模拟

Numerical optimization of micromixer during CPA loading for oocyte

为了减小卵母细胞低温保存的渗透损伤与毒性损伤,微流体装置被应用于低温保护剂的连续添加和去除。针对卵母细胞保护剂添加过程,建立了基于S形混合通道的微混合器模型,研究了通道的几何参数与操作参数对流体混合过程的影响,并对其进行了理论优化。结果表明：混合通道的高度增加,或宽度减小都会增加流体的混合性能;当Re数的范围在0.04~11.2,流体处于层流状态,混合仅靠分子扩散实现,随着Re数的增大,分子扩散的时间减少,两股流体的混合长度增加,混合效果变差;弯道产生的二次流对流体的扩散混合起着重要作用,明显提高了流体的混合效率,同时弯道并不会增大流体流动的局部阻力。这些结论可为微混合器的优化设计及后期卵母细胞低温保存试验提供参考。

In order to minimize osmotic and toxic damage to oocytes during cryopreservation,microfluidic device has been applied to the continuous loading and unloading of cryoprotective agents（CPAs）. In this study,a micromixer model based on S-shaped channel was established for the process of CPA loading,the effects of channel geometrical and operating parameters on the fluid mixing performance were investigated,and theoretical optimization was carried out for them. Results showed that the fluid mixing performance increased with the increase of height and decrease of width of the mixed channel. When the Reynolds number was in the range of 0. 04 ~ 11. 2,the two-fluid was mixed only by the molecular diffusion at a laminar flow state,and with the increase of Reynolds number,the diffusion time decreased and the mixing length increased; the secondary flow from curve channel played an important role in the fluid mixing,significantly improved the mixing efficiency. Meanwhile,the curve channel will not increase local resistance of fluid flows. These conclusions have the certain reference values for the optimal design of the micro mixer and later oocyte cryopreservation experiment.