Coefficient of restitution mediated by a diamagnetic interaction

Eur Phys J E Soft Matter. 2016 Jul;39(7):74. doi: 10.1140/epje/i2016-16074-9. Epub 2016 Jul 27.

Abstract

We study how a magnetic bead bounces onto a horizontal diamagnetic conducting plane. The bead, falling down by gravity from a certain height, produces an Eddy current that creates a repelling force. For low velocities the bead is trapped by the surface, for intermediate ones it escapes. In such a case the induced current changes its sign, and so does the force. The balance between diamagnetic and viscoelastic interactions determines the bouncing dynamics. We find experimentally the restitution coefficient as a function of the impact speed of the bead and develop, taking into account simple energetic considerations, a model able to reproduce our findings.

Keywords: Flowing Matter: Granular Matter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Elasticity
  • Gravitation
  • Magnetics*
  • Microspheres*
  • Viscosity