Highly Stretchable Flame-Retardant Skin for Soft Robotics with Hydrogel-Montmorillonite-Based Translucent Matrix

Flame-retardant coatings are crucial for intelligent systems operating in high-temperature (300-800 degrees C) scenarios, which typically involve multi-joint discrete or continuous kinematic systems. These multi-segment motion generation systems call for conformable yet resilient skin for dexterous work, including firefighting, packaging inflammable substances, encapsulating energy storage devices, and preventing from burning. In fire scenes, a flame-retardant soft robot shall protect integrated electronic components safely and work for navigation and surveillance effectively. Here, we establish fire-resistant robotic mechanisms with montmorillonite (MMT)-biocompatible hydrogel skin, offering effective flame retardancy (similar to 78 degrees C surface temperature after 3 min in fire) and high post-fire stretchability (similar to 360% uniaxial tensile strain). Fatigue test results in the MMT-hydrogel polymer matrix to portray a change in post-fire energy consumption of similar to 21% (between the first cycle and the 200th cycle), further indicating robustness. MMT-hydrogel synthetic skin medium is then applied to everyday household items and electronics, offering appealing protections in fire scenes (