Even if it’s just moving a pointer or altering a display, a mechatronic system must “do” something. Motors are needed for the industrial robot to move an end effector, such as a gripper, whereas another system’s output may include heaters. The mechatronic engineer should not be in a hurry to go to the catalog and select an electric motor. Motors are a wonderful playground for electrical engineers to debate the advantages and downsides of axial flux, windage losses, rotor resistance, and commutation. The mechatronic engineer isn’t sure if the solution isn’t anything hydraulic or pneumatic. This section attempts to put a few of the vast variety of actuators into perspective.