Self-Healing Natural Rubber Based on the Double Cross-Linked Networks for Fabrication of the Flexible Electronic Sensor

The development of tough, dependable, and durable flexible electronic sensors has always posed a forward-thinking challenge due to the traditional sensors' functional degradation caused by intricate deformation or accidental damage. In this work, we designed a type of dual cross-linked self-healing natural rubber (NRFB) by utilizing the monomer with double vinyl groups (HEF) and employing the Diels–Alder reaction between furan rings and maleimide. The incorporation of dual cross-links not only imparts NRFB with robust and resilient mechanical properties but also confers upon them excellent self-healing capabilities. The tensile strength, breaking elongation, and self-healing efficiency of NRFB can reach up to 7.39 MPa, 664%, and 91%, respectively. The self-healing strain sensor was then assembled by depositing a nanostructured conductive layer (silver film) onto an elastomeric substrate with self-healing properties. Irrespective of pre- and postself-healing, the self-healed strain sensors exhibit exceptional precision in capturing a wide range of human activities, encompassing both substantial limb movements and subtle physiological responses. This efficacious strategy may serve as an inspiration for the development of next-generation flexible sensors, wearable technology, and tactile-sensing skin.