Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, 525-8577, Japan.
Ritsumeikan Advanced Research Academy, Kyoto, 604-8502, Japan.
Sci Rep. 2023 Jun 9;13(1):9428. doi: 10.1038/s41598-023-36516-3.
Transportation of magnetized particles (MPs) against gravity is possible by applying a magnetic field to the particles. This transport phenomenon of MPs in microdroplets can be quantitatively assessed by determining the contribution of individual forces acting on the MPs. We studied the selective transportation of MPs in microdroplets. MPs in microdroplets were transported in the opposite direction to gravity when we applied an external magnetic field larger than a threshold value. We modulated the intensity of the external magnetic field and selectively manipulated the MPs. As a result, MPs were separated into different microdroplets based on their magnetic properties. Our quantitative investigation of transport dynamics shows that the threshold magnetic field depends only on the magnetic susceptibility and the density of MPs. This is a universal criterion for the selective transport of magnetized targets such as magnetized cells in microdroplets.
通过向粒子施加磁场，可以实现对磁化粒子（MPs）的重力反向运输。通过确定作用于 MPs 的各个力的贡献，可以定量评估 MPs 在微滴中的这种运输现象。我们研究了 MPs 在微滴中的选择性运输。当施加大于阈值的外部磁场时，MPs 在微滴中朝着与重力相反的方向运输。我们调节外部磁场的强度，并选择性地操纵 MPs。结果，根据 MPs 的磁性能，它们被分离到不同的微滴中。我们对运输动力学的定量研究表明，阈值磁场仅取决于 MPs 的磁化率和密度。这是在微滴中选择性运输磁化目标（如磁化细胞）的通用标准。
