Dynamic trajectory analysis of superparamagnetic beads driven by on-chip micromagnets.
Dynamic trajectory analysis of superparamagnetic beads driven by on-chip micromagnets.
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DOI：
10.1063/1.4936219
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发表时间：
2015-11
影响因子：
3.2
通讯作者：
Xinghao Hu;R. Abedini-Nassab;Byeonghwa Lim;Ye Yang;M. Howdyshell;R. Sooryakumar;B. Yellen;Cheolgi Kim
中科院分区：
文献类型：
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作者：
Xinghao Hu;R. Abedini-Nassab;Byeonghwa Lim;Ye Yang;M. Howdyshell;R. Sooryakumar;B. Yellen;Cheolgi Kim
我们研究了超顺磁珠在平面内旋转磁场作用下围绕图案化磁盘外围运动的非线性动力学。实验中观察到三种不同的动力学状态：(1)低驱动频率下的锁相运动；(2)第一临界频率fc1以上的相位滑移运动；(3)第二临界频率fc2以上的相位隔离运动。用Janus粒子进行的实验证实，珠子是通过滑动而不是滚动来移动的。其余的实验是在球形各向同性磁珠上进行的，其中使用自动粒子位置跟踪算法来分析磁珠的动力学。锁相区和滑移区的实验结果与数值模拟结果吻合较好。需要更多的假设来预测相绝缘状态的开始，在这种情况下，珠子被困在封闭的轨道上；然而，相绝缘状态的起源似乎是局部磁化缺陷的结果。这些结果表明，这三种动力学状态是非均匀振子中珠子运动的普遍特征。
We investigate the non-linear dynamics of superparamagnetic beads moving around the periphery of patterned magnetic disks in the presence of an in-plane rotating magnetic field. Three different dynamical regimes are observed in experiments, including (1) phase-locked motion at low driving frequencies, (2) phase-slipping motion above the first critical frequency fc1, and (3) phase-insulated motion above the second critical frequency fc2. Experiments with Janus particles were used to confirm that the beads move by sliding rather than rolling. The rest of the experiments were conducted on spherical, isotropic magnetic beads, in which automated particle position tracking algorithms were used to analyze the bead dynamics. Experimental results in the phase-locked and phase-slipping regimes correlate well with numerical simulations. Additional assumptions are required to predict the onset of the phase-insulated regime, in which the beads are trapped in closed orbits; however, the origin of the phase-insulated state appears to result from local magnetization defects. These results indicate that these three dynamical states are universal properties of bead motion in non-uniform oscillators.