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Spontaneous Patterning of Confined Granular Rods

J. Galanis·D. Harries·D. L. Sackett·W. Losert·R. Nossal
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Abstract

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.

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J. Galanis, D. Harries, D. L. Sackett, W. Losert, R. Nossal. 2005-08-10. Spontaneous Patterning of Confined Granular Rods. https://doi.org/10.1103/physrevlett.96.028002

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