Preliminary validation of Sm–Fe–N magnetic silicone rubber for a flexible magnetic actuator

In this paper, we present a new approach for a flexible magnetic actuator (FMA) using Sm–Fe–N magnetic silicone rubber (MSR) that has a higher degree of freedom (DOF) in shape, flexibility, ease of fabrication and combinative ability than permanent magnets. To verify its potential for use in an FMA, we examined its magnetic and elastic properties and focused on magnetic torque control within a uniform rotating magnetic field. Silicone rubber liquid and hardener were mixed with Sm–Fe–N powder and poured into a mold. The fabricated Sm–Fe–N MSR included Sm–Fe–N powder of 13.5, 17.3, and 21.2 vol% ratio. The physical and elastic properties were determined by a vibrating sample magnetometer (VSM) and elastic load, respectively. Furthermore, we fabricated two FMAs (multiple-magnetic anisotropy type and spiral-type), and evaluated the suitability of the Sm–Fe–N MSR for magnetic wireless actuators based on magnetic torque control.