Hierarchically Reconfigurable Soft Robots with Reprogrammable Multimodal Actuation

Reconfigurable soft robots exhibit superior flexibility and adaptability when coping with complex environments and variable tasks. However, conventional modular design strategy based on soft actuator modules with specific structure and actuation mode as the basic constructing element for reconfigurable soft robots always has limited reprogrammability or scalability. Here, a hierarchical reconfigurable strategy is reported that not only offers conventional module reconfiguration as the first level to build different robot prototypes, but also provides the elastically-guided multimodal actuation (contraction, bend, and twist) as the second level which can be reprogrammed to construct different actuator modules. This strategy deepens the modularity to a higher dimensionality and provides more choices for robots to adjust various conformations and functions as needed, for example, a peristalsis robot, an omnidirectional crawling robot, and a soft manipulator can be easily constructed using the module-level reconfiguration. Moreover, soft manipulators with various preprogrammed deformation trajectories based on the mode reconfiguration are proven to dramatically reduce the operation difficulty and cost in potential applications such as environment detection and human-robot interaction. This work provides a hierarchical framework for reconfigurable soft robots and may open up a new way for modular design.