【摘要】 针对微流道内DNA等生物大分子动态变化问题,合理构建颗粒负载型流动系统。采用球—棒蠕虫链模型表示DNA链,应用布朗动力学对DNA在微流道内的运动轨迹进行数值模拟。利用有限元法求解Navier-Skoes方程,得到矩形微流道内3D稳定的压力流场速度分布,并根据Stokes定律,将其耦合到布朗动力学中,继而得到DNA在压力流场中的动态变化过程。模拟结果表明,流经3D微管道时,DNA链不仅会发生一定的变形,而且会在流场作用力、布朗随机力和DNA链弯曲作用力的综合作用下,朝向管道中心区域移动,所得DNA动态特性与试验结果吻合。当DNA浓度较低时,DNA在流场中的运动虽然会对微流道内流体的流动速度产生一定的反作用,但是这种反作用较为微弱。布朗动力学与有限元法相结合的数值模拟方法可应用到相关聚合物的研究领域中,拓宽微流控芯片和生物芯片的设计思路。更多还原

【Abstract】 To study the dynamic process of DNA,a proper model of particle-laden flow system is presented.Brownian dynamics method is used to simulate the trajectory of DNA in the microchannel where DNA is modeled by the wormlike bead-rod chain. Navier-Stokes equation is numerically solved by using finite element method to obtain the distribution of flow field in three-dimensional rectangular microchannel.The dynamics of DNA under pressure-driven flow can be obtained by considering interactions of flow filed and DNA chain according to the Stokes law.The results show that the DNA chain not only experiences certain deformation but also moves towards the central region of microchannel owing to the coupling effect of hydrodynamic force, random force and bending force.Simulated dynamic characteristics of DNA agree well with the experimental data.When the concentration of DNA is low,the effect of DNA chain on the flow field is very small.The combination of Brownian dynamics and finite element method can be applied to study the polymer behaviors and get a better insight into designing the microchip and biochip.更多还原