Magneto-rheological solids

Abstract The physical properties, based on simulation results, of model fluids and solids bearing an electric or magnetic point dipole moment are described. Comparison is made with experimental data on ferrofluids and electro- or magneto-rheological fluids. The qualitative agreement between experiment and simulation shows the interest of these simple models for the comprehension of physical systems where the dipolar interaction dominates. 

The systems of dipolar particles considered in this review are simple models for fluids or solids whose molecules bear a permanent dipole moment. They can also serve as credible models for suspensions like ferrofluids [1] or elec-tro(magneto)rheological fluids [2,3]. For spherically symmetric dipolar particles the interaction between a pair of particles separated by a distance nj and bearing dipole moments Hi and fij is given by... 

One example of such a substance is a fluid whose flow characteristics (rheology) can be changed from free flowing to almost solid in about 0.01 second by the application of an electromagnetic field. This magneto-rheological (MR) fluid was developed... 

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