An articulating mechanism for use in a single- or multiple-fluid-path painting robot is presented. The articulation design is particularly suitable as a wrist-joint and is free from the problems of dead space and single-fluid-path limitations found in conventional wrist-joint designs. The mechanism is based on coupling two cylindrical casings coaxially so that arm casing, wrist casing and the flange ends are coaxially joint about a shaft axis. The end sections of each components are sealed while leaving a fluid space of a given spacing between the outer and inner casings. The casings provide a fluid passage space extending in the direction of the casings and is provided with fluid delivery holes for the delivery of paint and other fluid medium. The designs include a blocking member so that cleaning of the robotic device, and quick maintenance or color changes can be carried out during production operation.