Non-linear Dynamics of Traveling Wave Magnetophoresis for Applications in Colloidal Separation

该奖项的研究目标是研究行波磁电泳在胶体分离中的非线性动力学应用。所提出的工作中使用的行磁场波是通过将均匀旋转磁场与微磁体阵列附近的局部磁场叠加而产生的。当外场以低频旋转时，磁珠锁定在势能最小值中，并与行波同步移动。在更高的频率下，磁珠往往会滑出势能最小值，导致磁珠运动速度减慢或完全停止运动。本提案的总体目标是调查最近在这种滑动中观察到的意外行为。，其中珠显示出强烈的非线性输运行为，并利用这种非线性来探索在磁分离中的新应用。在这项研究中，数值模拟将成为解释实验结果和指导该技术未来应用的主要工具。如果成功的话，这项工作将不仅带来基于附着在磁珠上的生物微生物的大小和/或类型来分类磁珠的新方法，而且还将揭示一阶非线性动力系统中尚未解决的问题。由于这项工作的高度跨学科性质，研究生和本科生将广泛接触动力学，电学和磁学，微加工，化学，生物学和计算机科学领域。传统黑人学院和大学(HBCU？s)或历史少数民族大学(HMU？S)，将在夏季的两个月里参与这项工作。此外，杜克大学的本科生将通过杜克大学普拉特研究员计划参与这项研究。

The research objective of this award is to investigate the non-linear dynamics of traveling wave magnetophoresis for applications in colloidal separation. The traveling magnetic field wave used in the proposed work is generated by superimposing a uniform rotating magnetic field with the local magnetic field near an array of micro-magnets. When the external field rotates at a low frequency, the magnetic beads become locked into the potential energy minima and move synchronously with the traveling wave. At higher frequencies, the magnetic beads tend to slip out of the potential energy minima, causing the bead to move less quickly or stop moving altogether. The overall goals of this proposal are to investigate the unexpected behavior recently observed in this ?slipping? regime, in which the beads display strongly non-linear transport behavior, and to use this non-linearity to explore a novel application in magnetic separation. Numerical simulations will be a dominant tool in this study both for interpreting the experimental results and for guiding future applications of this technique. If successful, the proposed work will lead not only to new methods for sorting magnetic beads based on size and/or the type of biological micro-organism attached to the bead, but will also reveal insight into unresolved problems in first order non-linear dynamical systems. Due to the highly interdisciplinary nature of this work, graduate and undergraduate students will have broad exposure to the fields of dynamics, electricity and magnetism, microfabrication, chemistry, biology and computer science. Minority studies from Historically Black College and Universities (HBCU?s) or Historically Minority Universities (HMU?s), will be included in this work for two summer months. In addition, undergraduate students from Duke University will participate in this research through the Duke University Pratt Fellows program.