Enhanced Mechanical-Magnetic Coupling and Bioinspired Structural Design of Magnetorheological Elastomers

Magnetorheological elastomers (MREs) are innovative materials composed of ferromagnetic particles embedded within a polymer matrix, enabling real-time tunability of mechanical properties through external magnetic fields, thereby generating pronounced mechanical-magnetic coupling effects. However, the mechanical performance of MREs, particularly their load-bearing capacities under dynamic conditions, remains constrained by the limitations of conventional matrix materials. In this study, shear-stiffening gel (SSG), exhibiting viscoelastic mechanical behavior, is incorporated into magnetorheological elastomers to develop magnetorheological shear-stiffening elastomer (MSSE) through a high-temperature and high-pressure vulcanization process. The mechanical-magnetic coupling behavior of these composites is systematically evaluated utilizing a series of mechanical experiments across varying strain rates. Notably, the interaction between carbonyl iron particles (CIPs) and the molecular chains within the shear-stiffening matrix significantly enhanced the magnetorheological effects of MSSEs, particularly under dynamic impact loadings. Leveraging the adjustable modulus of MSSEs and drawing inspiration from the microstructural characteristics of beetle exoskeletons, a beam-structured 3D buffer device is designed. This device demonstrates superior energy absorption capacity, underscoring its potential for advanced flexible protection applications.