Design and development of a hyper-redundant binary active laparoscopic manipulator

The subject of this article is the development of a prototype hyper-redundant laparoscopic tool. The manipulator consists of cascaded modules which are powered by Shape Memory Alloy wires (NiTi), acting as binary actuators with two stable states. As a result, the repeatability of the manipulator´s movement is ensured, alleviating the need for sensing of the manipulator´s joint-positions. Each module is composed of three active prismatic actuators in a tripod configuration providing a 3-DOF (two rotational and one translational) maneuverability for each joint. I²C-networked microcontrollers activate the individual tendons in each joint. Certain design aspects as well as the kinematics of the binary manipulator are presented followed by experimental studies on the laparoscopic tool prototype.