A general soft robot module driven by twisted and coiled actuators

摘要

Soft robots usually have soft structures and multiple degrees of freedom, and they are capable of large deformations and safe human-machine interactions. But unlike rigid robots which can be easily assembled from multitudinous general components, the fabrications of soft robots are more difficult. This work presents a general soft robot module that can be assembled into a great variety of soft robots. This module can bend in any direction and the bending angle can be controlled easily and accurately; it has a bar-like soft body made from silicone, and the bending deformation is actuated by multiple twisted and coiled actuators (TCAs) that are uniformly distributed around the soft body. The cost of the module is very low since the silicone is very cheap and TCAs are also very cheap as that they can be easily fabricated from polymer fibers such as fishing lines and sewing threads. A prototype was made, and an angle control system was established to control the bending posture of the module precisely. To verify the versatility of the module, a two-finger soft manipulator assembled by the module was made and its grabbing ability was tested.