Magneto-rheological foams capable of tunable energy absorption

While foams are widely used for absorbing kinetic energy, their capacities of energy absorption are generally not tunable in applications. In this paper, Magneto-rheological elastomers have been fabricated into the form of foams. Here, we show that the magneto-rheological foams can significantly vary their capacities of energy absorption in response to uniform magnetic fields. We develop a theoretical model to account for the magnetomechanical properties of magneto-rheological foams. We find that the tunable energy absorption of magneto-rheological foams is mainly attributed to the Maxwell stress induced by the applied magnetic field. The theoretical prediction matches well with experimental results.