Morphological Transition between Patterns Formed by Threads of Magnetic Beads

Magnetic beads attract each other forming chains. We pushed such chains into an inclined Hele-Shaw cell and discovered that they spontaneously form self-similar patterns. Depending on the angle of inclination cell, two completely different situations emerge, namely, above static friction patterns resemble stacking a rope below look similar to fortress from above. Moreover, locally first pattern forms square lattice, while second exhibits triangular symmetry. For both patterns, size distributions enclosed areas follow power laws. characterize morphological transition between experimentally numerically explain change in polarization as competition friction-induced buckling gravity.