A Periodic Deformation Mechanism of a Soft Actuator for Crawling and Grasping

Periodic locomotion in nature has provided many inspirations for soft actuators. Compared with rigid actuators, soft actuators can transform into versatile shapes to adapt to different working environments and are able to interact with the human in a safer manner because of their compliance. However, soft actuators often suffer from complex structures designs and complicated sequences of stimuli to achieve periodic locomotion. To overcome this shortcoming, a periodic deformation mechanism based on strain energy storing is proposed in this paper. Guided by this mechanism, a simple soft actuator is designed without complicated control systems. The soft actuator involves shape memory alloy and silicon rubber. Crawling and grasping of the soft actuator are achieved by electrical heating methods. The proposed mechanism can provide inspiration for the design of soft actuators, smart wearable equipment, and medical devices.