Magnetorheological (MR) materials are intelligent materials with ferromagnetic particles of micron size suspended in a non-magnetic medium and are ideal materials to develop semi-active devices. Because of their advantages, including lightweight, high controllability, fast-response, and energy-efficiency, the actuation mechanism based on MR technology has been widely used in robotic actuation. Several types of novel actuation joints integrated with MR components were proposed and designed in this paper. Specifically, the joint actuation equipped with multidisc MR dampers and a motor relies on the MR dampers to change the output direction instead of reversing the motor; this mechanism leads to a faster actuation response speed. Secondly, to miniaturize the size and improve the output, another quasi-passive actuation joint integrated with MR bearings and a torsional spring is invented for exoskeleton argumentation. The exoskeleton with elastic MR actuation can store kinetic energy from human body locomotion repeatedly and release the accumulated energy instantaneously to realize high-level mobility. The strong explosive output capacity of the actuations is effective in raising the jump height and jumping off capability for human beings. In summary, this paper presents new MR joints and their applications to improve the robotic technology.

magnetorheological joint,robotics,exoskeleton,engineering applications,actuation