Coiled Conductive Polymer Fiber Used in Soft Manipulator as Sensor

Soft robots are of particular interest to the robotics community due to their high compliance and safety for humans. However, soft sensors that can be easily embedded in soft robots are still under exploration. This work presents a novel soft sensor made by coiling conductive polymer fiber. The resistances of the coiled conductive polymer fibers (CPFs) change with their length. An application of CPF in soft robot as sensor is shown as well. A soft manipulator actuated by a motor and actuation cables is made. CPF made of conductive nylon fiber is embedded into the soft manipulator. When the manipulator bends, the resistance of CPF will change due to the change of its length. The relation between the resistance change rate and the bending angle is built to measure the angle via CPF. An angle control system that gets rid of rigid sensors based on the sensing function of CPF is established. This work provides a novel method for the sensing of soft robots.