Magnetically Induced Unjamming

Granular materials are collections of athermal, macroscopic particles that can exhibit the properties of a solid or a liquid independent of temperature. The transition from a liquid-like state to a solid-like state or vice-versa is known as the jamming transition. Jamming is present in many industrial applications ranging from robotics to grain silos to pharmaceuticals. For our project, we seek to control the jamming transition of a ferromagnetic granular material (iron filings) through the application of a time varying, external magnetic field. This magnetic field is created either through the use of a permanent magnet that rotates under the granular material creating magnetic fields with sinusoidal waveforms or a system of four solenoids placed laterally around the reservoir which can create magnetic fields with arbitrary waveforms. Each setup is capable of causing the iron filings to vibrate, producing a liquid-like state for the granular material allowing us to control the jamming transition of the granular material.