The polymeric material (e.g. silicone rubber) in its liquid state is mixed with iron powder and several other additives to enhance their mechanical properties.
Curing in the presence of a magnetic field causes the iron particles to arrange in chain like structures resulting in an anisotropic material.
[3] MREs can be classified according to several parameters like: particles type, matrix, structure and distribution of particles:[citation needed] In order to understand magneto-mechanical behaviour of MREs, theoretical studies need to be performed which couple the theories of electromagnetism with mechanics.
[4][5] Magnetopolymers with large remanence are typically formed by combining hard-magnetic particles with a polymer matrix.
Programmable magnetopolymers embed athermal ferromagnetic particles in droplets of low melting point materials in polymer matrices.