Techniques for a surgical system are provided that allow controlling a force applied by an electromechanical surgical tool coupled to an electromechanical surgical arm. A force limiter can be associated with at least one of the surgical arm and the tool and is used to limit the force applied by jaws of the tool to tissue when the tissue is engaged therebetween or when the tissue is otherwise manipulated. The force can be limited to a maximum force value, which can be preselected, and it can be adjustable based on user input or automatically. Also are provided techniques for a surgical system that allow controlling a stiffness of an electromechanical passive arm coupled to a fixture and having an active arm mounted thereon. The stiffness is adjusted, either manually or automatically, by adjusting a friction at a joint of the arm based on an angle at the arm's joint.