Mechanoreception and Proprioception of Soft Robots

Mechanoreception plays a significant role in the soft robotic field to improve safety and task performance during the interaction with the external environment and enhance applicability for the soft robots in our daily life. It can be implemented by proprioception, detecting the inner robot’s states, and exteroception, perceiving the external mechanical stimuli in the unstructured environment. Diverse approaches have been presented to enable the soft robot with these excellent characteristics. However, the state-of-the-art mechanosensory strategies mainly focus on inserting the deformable sensors into the soft robots, leading to complicated fabrications and challenging applications. To this end, we present a novel scheme to realize the mechanoreception ability with pressure-based sensors for the soft robot driven by soft elastic chambers, especially the bellow and origami-inspiring actuators. We present the actuator’s displacement proprioception method based on Boyle’s law at the actuator level. Moreover, we also propose an improved sensor solution to overcome the unstable temperature in the chamber and the bending movement of the actuator. In addition, we also describe proprioceptive modeling approaches to the antagonistic bellow unit, the proprioceptive origami soft actuator joint, the three-segment soft manipulator, and proprioceptive modeling approaches to the corresponding soft robots, including 1-DOF soft gripper, a high-payload proprioceptive gripper, and the soft manipulator. At last, we present three mechanoreceptive applications, object stiffness detection, object contour scanning, and object size and weight recognization, to demonstrate the mechanoreception ability. These approaches provide an alternative solution to achieving soft robots’ internal and external detections.