Renovating Stability and Performance in Magnetorheological Fluids Through Particle Size and Shape Anisotropy

Magnetorheological (MR) fluids are smart materials consisting of magnetic particles in a non-magnetic medium, undergoing phase transitions under a magnetic field to generate yield stress. However, sedimentation and limited particle content hinder their industrial application, balancing high yield stress with stability. This study introduces an innovative MR slurry using Sendust particles, achieving superior yield stress and sedimentation stability compared to traditional systems. Flake Sendust particles demonstrate enhanced yield stress at low magnetic fields due to their lower demagnetization factor, outperforming bulk Sendust despite lower packing volumes. These findings emphasize the critical role of particle morphology in optimizing MR fluid performance. The slurry maintains its magnetorheological properties while offering tunable yield stress, making it suitable for diverse applications. This research addresses traditional trade-offs in MR fluid design, paving the way for advanced MR slurries in sensors, actuators, energy harvesters, haptic devices, and biomedical systems.