Pulling Your Strings

ecently, there has been an exciting array of new robotic devices especially designed for human-machine interaction. Consequently, a new field related to haptics has flourished: development of simple and often inexpen-sive devices that provide force feedback or positioning of a human operator as controlled by customized computer programs. One method, which seems to be less explored, is the use of cable actuators for such a robot. Cables are advantageous because of remote actua-tion, flexibility, and low weight. Tendons are examples of cables used in nature. The body uses these natural tension ele-ments by keeping them close to the joints, which generates a small moment arm that limits torque but allows large and ofte