A Multi-Facet-Effector Soft Robot in Polyhedral Configuration for Multidirectional Function Reuse

Soft robots are known for their adaptability in unstructured environments, providing the flexibility required for complex tasks. Existing designs are often tailored explicitly for particular functionalities, lacking the ability to accommodate diverse task requirements. To address the challenges, we propose an innovative approach employing Multi-Facet-Effector (MFE) in the design of a soft robot. The MFE functions both as a gulp gripper (MFG) and a parallel arm (MFA), achieving versatile capabilities without the need for intricate and specific designs. Three Soft-Bellowed Actuators (SBAs) constitute the identical regular triangle in each facet of an octahedral-shaped configuration. When working as the MFG, the robot exhibits the capability to grasp objects within a diameter range of 36.3-109.1 mm, with the maximum holding force up to 7 N. This gripping stability extends to objects of various shapes, rigidities, and weights. When working as the MFA, experimental results reveal six degrees of freedom (DOFs) at the top pose, with five DOFs exhibiting symmetric behaviors. The translational distance along the X and Y axes reaches 42.2 mm, while the Z-axis spans from -67.1 to 29.4 mm. Unidirectional rotation angles around the X, Y, and Z axes are 27.2°, 30.7°, and 35.7°, respectively. A kinematic model for the MFA movements is established and validated through experiments. The inherent characteristic of identical motion and functionality across each facet of the MFE soft robot allows for the efficient utilization of repetitive configurations. Through coordinated actions among the facet-effectors, the robot is capable of executing a variety of tasks in three-dimensional (3D) space, such as multi-facet manipulations and climbing on complex spatial terrains.