Spontaneous patterning of confined granular rods.
Vertically vibrated rod-shaped granular materials confined to quasi-2D containers self-organize into distinct patterns. We find, consistent with theory and simulation, a density dependent isotropic-nematic transition. Along the walls, rods interact sterically to form a wetting layer. For high rod densities, complex patterns emerge as a result of competition between bulk and boundary alignment. A continuum elastic energy accounting for nematic distortion and local wall anchoring reproduces the structures seen experimentally.
NICHD, National Institutes of Health, Bethesda, Maryland 20892-0924, USA.
Jennifer
J
Galanis
Daniel
D
Harries
Dan L
DL
Sackett
Wolfgang
W
Losert
Ralph
R
Nossal
D016880:Anisotropy; D003198:Computer Simulation; D004548:Elasticity; D050866:Liquid Crystals; D008962:Models, Theoretical; D044367:Phase Transition