Smart magnetorheological soft materials: properties, mechanisms, and applications

Abstract Magnetorheological materials, including MR Fluids, MR Elastomers, MR Greases, MR Foams, MR Gels, and MR Plastomers are smart materials whose rheological properties change reversibly under magnetic fields. This review examines their development, characteristics, and applications, emphasizing MR Polymer Gels and MR plastomer as an emerging class addressing key limitations of conventional MR materials technologies. Each MR material has distinct trade-offs and MR Fluids offer rapid response but suffer sedimentation. MR Elastomers eliminate sedimentation but need continuous applied magnetic fields and show limited load capacity. MR Greases combine lubrication with controllable viscosity and MR Foams provide lightweight structures with tunable damping but reduced field response. MR Gels bridge MR fluid and MR elastomer properties while reducing sedimentation. MR Plastomer composed of carbonyl iron powder in lightly cross-linked polymers demonstrate superior sedimentation stability, rapid response, and strong field induced changes. The review covers MR Plastomer classification by particle distribution into isotropic or anisotropic types and matrix composition. Fabrication techniques include mixing, curing, and field assisted alignment. Critical properties examined are mechanical, magnetic, and electrical. Their Performance factors analyzed include carbonyl iron content, additives, polymer selection, and applied field effects. MR Plastomer damper performance is assessed through damping force, dynamic range, response time, and energy dissipation. Outstanding challenges include matrix stability, particle redistribution, and predictive modeling. Future priorities encompass microstructure optimization, durability enhancement via advanced formulations, and physics based models for adaptive structures, vibration isolation system, and sensing applications.