Gu Hongri, Chen Yonglin, Lüders Anton, Bertrand Thibaud, Hanedan Emre, Nielaba Peter, Bechinger Clemens, Nelson Bradley J
Department of Physics, University of Konstanz, Konstanz 78464, Germany.
Institute of Robotics and Intelligent Systems, ETH Zurich, Zurich CH-8092, Switzerland.
Device. 2024 Jul 19;2(7):100403. doi: 10.1016/j.device.2024.100403.
Surface-engineered magnetic microparticles are used in chemical and biomedical engineering due to their ease of synthesis, high surface-to-volume ratio, selective binding, and magnetic separation. To separate them from fluid suspensions, existing methods rely on the magnetic force introduced by the local magnetic field gradient. However, this strategy has poor scalability because the magnetic field gradient decreases rapidly as one moves away from the magnets. Here, we present a scalable high-throughput magnetic separation strategy using a rotating permanent magnet and two-dimensional arrays of micromagnets. Under a dynamic magnetic field, nickel micromagnets allow the surrounding magnetic microparticles to self-assemble into large clusters and effectively propel themselves through the flow. The collective speed of the microparticle swarm reaches about two orders of magnitude higher than the gradient-based separation method over a wide range of operating frequencies and distances from a rotating magnet.
表面工程化磁性微粒因其易于合成、高比表面积、选择性结合和磁分离等特性而被应用于化学和生物医学工程领域。为了从流体悬浮液中分离出这些微粒，现有的方法依赖于局部磁场梯度引入的磁力。然而，这种策略的可扩展性较差，因为随着远离磁体，磁场梯度会迅速减小。在此，我们提出了一种使用旋转永磁体和微磁体二维阵列的可扩展高通量磁分离策略。在动态磁场下，镍微磁体可使周围的磁性微粒自组装成大的团簇，并在流体中有效地自行推进。在广泛的工作频率和与旋转磁体的距离范围内，微粒群的集体速度比基于梯度的分离方法高出约两个数量级。
