| 초록 |
Chain-like self-assembly has been demonstrated by applying magnetic stimuli to microscale composite of a polymer matrix and magnetic particles. Toward a reversible and stepwise magnetic self-assembly, we prepared micropillars with a high loading of magnetic particles. Pillar-top is magnetically responsive while pillar-base is magnetically-inert. Under an external magnetic field, quadrupolar magnetic attraction is generated between adjacent dipolar pillars whose magnetic polarities are arranged from S to N pole. After a critical magnetic flux density, two micromagnet-like pillars begin to pair up. At a higher magnetic flux density, the number of assembled pillars increased to four. Above a magnetic flux density of 0.4 T, long-range ordered connectivity is eventually accomplished by the magnetic assembly. Detailed mechanisms and governing parameters for this system would be explored according to the geometry and arrangement of pillar arrays against the applied external magnetic field. |
