Magnetorheological Elastomers - Material Properties and Actuation Capabilities

Magnetorheological elastomers (MRE) are composite materials, which consist of a soft elastomer matrix filled with soft-magnetic particles. Mechanical and magnetic properties of silicone-based MRE with iron particles in different concentrations as well as their alteration in a magnetic field with variable strength are described in this paper. By applying a magnetic field already during the preparation of MRE bodies, magnetic elastomer materials with anisotropic properties are generated. The mechanical, magnetic and electric properties of such anisotropic MRE materials were studied as well. Beside the exploitation of MRE for applications of vibration reduction, these materials can also be utilized for actuation purposes. The working principles of linear and radial MRE actuators are described. Moreover, some possible applications of linear MRE actuators for haptic feedback and precisely controllable pumps as well as the possible use of radial MRE actuators for proportional valves and for locking devices are outlined in the paper as well.