Which type of joints in robotic arms allows rotation around an axis?

Revolute joints are specifically designed to allow rotation around a single axis. In the context of robotic arms, these joints enable the arm to pivot and articulate in a way that mimics the rotational movements found in joints of living organisms, such as the elbow or knee. The ability to rotate around an axis is crucial for tasks that require a range of movement and flexibility in positioning, such as reaching or manipulating objects in various orientations.

In contrast, prismatic joints allow linear movement along an axis but do not provide any rotational capability. Cylindrical joints combine both rotational and linear movement, but their primary function is predominantly in applications requiring both forms of motion together rather than purely rotational. Fixed joints, as the name suggests, do not allow any movement, making them unsuitable for applications requiring articulation. Thus, the capacity for rotation around an axis is a distinctive characteristic of revolute joints, confirming their role in robotic arm operation.