An Energy-Efficient Soft Robotic Gripper with Shape Locking and Sensing

Soft robotic grippers offer an innovative alternative to traditional rigid grippers, yet they still face significant challenges in energy efficiency and form self-locking. To address these issues, this study proposes a soft robotic gripper driven by a pre-stressed flexible plate and Twisted String Actuator (TSA), integrating a Supercoiled Polymer (SCP) flexible strain sensor for real-time self-perception of the gripper's morphology. Experimental validation demonstrates that the gripper can maintain its grasping posture in a power-off state, exhibiting excellent self-locking performance. By establishing a correlation between SCP resistance and the gripper's angle, the experimental results indicate that the developed fitting model can accurately infer morphological changes of the gripper, with root mean square errors (RMSEs) of 1.79° and 1.39° in two independent experiments. These findings suggest that by monitoring changes in SCP resistance, high-precision perception and control of the soft finger morphology could be achieved.