Development of a Compact Magnetorheological Fluid Clutch for Human-Friendly Actuator

There is a strong demand for a human–machine-coexistent machine, e.g., a power-assist system or a computer-aided rehabilitation system, in the context of the super-aging society. In such a human–machine-coexistent system, it is important to guarantee hardware-level safety by utilizing human-friendly actuators. In this study, we have developed a compact magnetorheological fluid clutch (CMRFC) for human-friendly actuators. In this paper, at first, the basic design of the CMRFC and developments of 5- and 40-Nm class devices are explained. Then we discuss experimental results on the basic characteristics of these devices. In the final part, a new magnetorheological fluid that includes nano-sized particles is discussed.