A Self-healable, recyclable and degradable soft network structure material for soft robotics

Soft materials enable soft robots to accommodate unstructured working environments robustly. However, they may be easily damaged and destroyed due to their weak mechanical properties. Moreover, most soft materials are not repairable or degradable after being broken or abandoned, resulting in new environmental burdens. Here, a self-healable, recyclable, and degradable soft material (SRDSM) with a network structure formed with gelatin and polyvinyl alcohol (PVA) is reported. The SRDSM exhibits a fracture strength of 3–4 MPa and a stretchability of up to 300 %-400 % by controlling the composition ratio and drying time. Results show that the SRDSM can recover 90 % of its original mechanical strength after healing and 95 % after recycling. An SRDSM-based soft gripper is demonstrated that can be self-healed under thermal cycling after minor damage. It can be recycled and remanufactured to restore its original functionality after severe damage. Furthermore, the soft gripper can decomposes and degrades entirely after contact with water. This research provides an enabling material to develop environmental-friendly and recyclable soft robots, reducing their negative environmental impact.