A suspension of micro- or nano-magnetic particles dispersed in a nonmagnetic carrier medium is called a magnetorheological (MR) fluid. MR fluids are smart materials that undergo rapid and reversible changes in rheological properties under an external magnetic field. The rheological properties of MR fluids can be easily controlled through manipulation of the magnetic field strength. Because of their unique and fast reversible changes in rheological properties, MR fluids are widely used in various devices and structures. However, they suffer long-term stability (particle sedimentation) problems because of the density mismatch between the suspended magnetic particle and the liquid medium. In previous studies, researchers have expended great efforts to simultaneously improve the stability and performance of MR fluids. Nevertheless, a trade-off relationship exists between the stability and the performance of MR fluids, that is, as MR performance increases, stability decreases, and vice versa. In this review, we recapitulate the findings of our group's recent achievements and address the conflicting issues. Reviewing the various routes will provide clues to solving the trade-off problem and suggest a guideline for developing high-performance and highly stable MR fluids.

分散在非磁性载体介质中的微米或纳米磁性颗粒的悬浮液称为磁流变 (MR) 流体。MR 流体是智能材料，在外部磁场下流变特性会发生快速和可逆的变化。MR 流体的流变特性可以通过控制磁场强度轻松控制。由于其独特且快速可逆的流变特性变化，磁流变液被广泛用于各种设备和结构中。然而，由于悬浮磁性粒子和液体介质之间的密度不匹配，它们会遇到长期稳定性（粒子沉降）问题。在之前的研究中，研究人员付出了巨大的努力来同时提高 MR 流体的稳定性和性能。尽管如此，MR流体的稳定性和性能之间存在权衡关系，即随着MR性能的提高，稳定性降低，反之亦然。在本次审查中，我们回顾了我们小组最近取得的成就并解决了相互矛盾的问题。回顾各种路线将为解决权衡问题提供线索，并为开发高性能和高度稳定的 MR 流体提出指导方针。