论文标题
通过惯性微流体中边界滑移对粒子位置的主动控制
Active control of particle position by boundary slip in inertial microfluidics
论文作者
论文摘要
惯性微流体能够基于特征几何形状和内在的流体动力效应将微通道中的颗粒聚焦并分离。然而，无法实时操纵悬浮颗粒在微通道中的垂直位置。在这项研究中，我们利用边界滑移效应来调节微通道中流体的抛物线速度分布，并提出一种计划，以主动控制粒子在惯性微流体中的垂直位置。具有单侧滑动边界的微通道的流场等效于相关滑动长度扩大的微通道的流场，并且两个微通道中的粒子平衡位置是一致的。然后，我们模拟三种典型颗粒的横向迁移，即微通道中的圆圈，椭圆形和矩形。与圆形颗粒的平滑轨迹不同，椭圆形和矩形颗粒的运动伴随着正常的波动和由于其非圆形几何形状而导致的不均匀旋转。结果表明，单侧滑动边界可以有效地控制颗粒的垂直平衡位置。因此，目前的方案使活动能够在垂直方向上操纵颗粒位置，并可以在惯性微流体中促进更准确的聚焦，分离和运输。
Inertial microfluidic is able to focus and separate particles in microchannels based on the characteristic geometry and intrinsic hydrodynamic effect. Yet, the vertical position of suspended particles in the microchannel cannot be manipulated in real time. In this study, we utilize the boundary slip effect to regulate the parabolic velocity distribution of fluid in the microchannel and present a scheme to active control the vertical position of particles in inertial microfluidics. The flow field of a microchannel with a unilateral slip boundary is equivalent to that of the microchannel widened by the relevant slip length, and the particle equilibrium positions in the two microchannels are consistent consequently. Then, we simulate the lateral migrations of three kinds of typical particles, namely circle, ellipse, and rectangle in the microchannel. Unlike the smooth trajectories of circular particles, the motions of the elliptical and rectangular particles are accompanied by regular fluctuations and non-uniform rotations due to their non-circular geometries. The results demonstrate that the unilateral slip boundary can effectively control the vertical equilibrium position of particles. Thus, the present scheme enables to active manipulate the particles positions in vertical direction and can promote more accurate focusing, separating, and transport in inertial microfluidics.
