Self‐Healing Polyurethane Elastomer Based on Crosslinked‐Linear Interpenetrating Structure: Preparation, Properties, and Applications

Despite tremendous advances in the preparation of self‐healing flexible strain sensor devices, it remains a great challenge to large‐area synthesis, relatively high mechanical strength, and sensitive sensing properties into one self‐healing materials system, which have received increasing interests because of their many potential applications. Herein, the design and synthesis of a crosslinked‐linear interpenetrating structure polymer containing disulfide and hydrogen bonds is reported to address this conundrum. The resulting self‐healable polymer is highly stretchable (up to 551.7%) with a high tensile strength (4.14 MPa) and excellent healing efficiency of similar to 90% at mild temperature without using any external reagents. Furthermore, a novel method for fabricating flexible sensor is also proposed to endow the resulted sensor with large‐area (20 cm × 12 cm), low cost, and outstanding sensitivity to strain, which makes it very suitable for human motion monitoring applications. This work will provide afflatus on future design, fabrication, and application of self‐healing flexible strain sensor devices.