title: Self-charging of identical grains in the absence of an external field.
abstract: We investigate the electrostatic charging of an agitated bed of identical grains using simulations, mathematical modeling, and experiments. We simulate charging with a discrete-element model including electrical multipoles and find that infinitesimally small initial charges can grow exponentially rapidly. We propose a mathematical Turing model that defines conditions for exponential charging to occur and provides insights into the mechanisms involved. Finally, we confirm the predicted exponential growth in experiments using vibrated grains under microgravity, and we describe novel predicted spatiotemporal states that merit further study.
authors.affiliation: Computational Physics for Engineering Materials, IfB, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Yoshimatsu
authors.affiliation: Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal, and Centro de Física Teórica e Computacional, Universidade de Lisboa, P-1749-016 Lisboa, Portugal.
authors.forename: N A M
authors.initials: NA
authors.lastname: Araújo
authors.affiliation: Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Wurm
authors.affiliation: Computational Physics for Engineering Materials, IfB, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland.|Departamento de Física, Universidade Federal do Ceará, 60451-970 Fortaleza,Ceará, Brazil.
authors.forename: H J
authors.initials: HJ
authors.lastname: Herrmann
authors.affiliation: Computational Physics for Engineering Materials, IfB, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland.|Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey, 08854, USA.
authors.forename: T
authors.initials: T
authors.lastname: Shinbrot