Magneto Rheological Elastomers are one of the Magnetic Smart Materials
and are analogous materials to Magneto Rheological Fluids. They are also composed of micron-sized magnetic particles but unlike Magneto Rheological Fluids the magnetic particles in Magneto Rheological Elastomers are dispersed in a polymeric matrix. This feature of Magneto Rheological Elastomers helps intrinsically to overcome the distinct shortcomings shown by Magneto Rheological Fluids e.g. the settling of the magnetic material in time due to the density mismatch of the particles and the carrier fluid which can diminish the magneto-rheological effect of these materials.
Polymeric Matrix: Magneto Rheological Elastomers are conventionally prepared by curing a polymeric matrix containing dispersed magnetic particles in the presence or absence of a magnetic field. As the polymer matrix is prepared in the presence (or absence) of a magnetic field, chainlike columnar structures or isotropic structures are formed by the magnetic particles fixed into the polymeric material. Magnetic Field: When such (an) isotropic Magneto Rheological Elastomers are exposed to an external magnetic field, the elastic modulus in a certain direction (x,y,z) of the material will change according to the strength of the applied magnetic field and its direction (depending on the internal distribution of the particles). These characteristics enable the possibility to make materials with (an) isotropic properties in each direction. The maximum increase in the modulus of Magneto Rheological Elastomers has been reported to be nearly 0.6 mPa (40% higher than the initial modulus).
Applications: Like Magneto Rheological Fluids, Magneto Rheological Elastomers can be utilized in several engineering applications that involve variable stiffness.