Stepwise Magnetic Self-Organization of Micropillar Arrays

초록

Long-range ordering of magnetic particles has been reported by generating magnetic dipole moments and dynamic swarming motion in aqueous medium under external magnetic field. However, the self-organization is not reversible and reliable because the position of magnetic particles is not stationary. Alternatively, we suggest periodic polymeric micropillar arrays with inclusion of magnetic particles for reversible and programmable magnetic self-organization in a stepwise manner. When magnetic field is applied, individual micropillars are magnetized and operate as micromagnets. The vicinal pair of pillar tops magnetically attract each other for magnetic self-organization while the pillar base is still fixed to the substrates. As the magnetic flux density increases, the paired micropillars undergo quad-body organization, and then the long-range connectivity of pillar tops is accomplished. We will discuss the influence of spacing and anisotropic cross-sections of the micropillars on the stepwise magnetic self-organization by investigating the geometry form factors such as rectangular, square and circular cross-section.