Dynamics and separation of circularly moving particles in asymmetrically patterned arrays.
Dynamics and separation of circularly moving particles in asymmetrically patterned arrays.
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DOI：
10.1103/physreve.88.042306
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发表时间：
2013-07
期刊：
影响因子：
--
通讯作者：
C. Reichhardt;C. Reichhardt
中科院分区：
文献类型：
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作者：
C. Reichhardt;C. Reichhardt
有许多例子的驱动和活性物质系统包含粒子，表现出不同的手性圆周运动，如游泳细菌表面附近或某些类型的自驱动胶体粒子。被动粒子的圆周运动也可以通过外部旋转驱动器来诱导。在这里，我们研究的粒子，在圆周运动和相互作用的周期性阵列的不对称的L形障碍。我们发现一系列的动态阶段作为游泳半径的函数，包括政权的粒子运动被整流，产生净直流运动。整流的方向随游动半径而变化，允许分离具有不同游动半径的颗粒。具有相同游动半径但不同手性的粒子也可以在衬底上沿不同方向运动并被分离。整流发生在对应于周期性轨道的游动半径的特定窗口中，在该周期性轨道中，粒子在每个旋转周期中与屏障相互作用一次或多次。整流效应对于热效应或扩散效应的增加是鲁棒的，并且在某些情况下甚至被这些效应增强。
There are many examples of driven and active matter systems containing particles that exhibit circular motion with different chiralities, such as swimming bacteria near surfaces or certain types of self-driven colloidal particles. Circular motion of passive particles can also be induced with an external rotating drive. Here we examine particles that move in circles and interact with a periodic array of asymmetric L-shaped obstacles. We find a series of dynamical phases as a function of swimming radius, including regimes where the particle motion is rectified, producing a net dc motion. The direction of the rectification varies with the swimming radius, permitting the separation of particles with different swimming radii. Particles with the same swimming radius but different chirality can also move in different directions over the substrate and be separated. The rectification occurs for specific windows of swimming radii corresponding to periodic orbits in which the particles interact one or more times with the barriers per rotation cycle. The rectification effects are robust against the addition of thermal or diffusive effects, and are in some cases even enhanced by these effects.