Supramolecular Cross-Linked High-Performance Self-Healing Elastomers toward Wearable Sensing Applications

Flexible conductive elastomers play a pivotal role in biosensing, electronic skin, and wearable devices. However, fabricating self-healing conductive elastomers with superior mechanical properties remains a formidable challenge. Here, we introduce a simple strategy for the preparation of a flexible elastomer that integrates stretchability, conductivity, and self-healing capabilities. Initially, the self-healing lipoic acid (LA) and conductive deep eutectic solvents (DES) are thermally initiated ring-opening copolymerized, yielding a linear copolymer P(LA-DES). This polymer is then integrated with linear polyurethane by intermolecular hydrogen bonds, followed by the incorporation of Fe3+ ions to form a dynamic cross-linked network containing disulfide bonds, hydrogen bonds, and metal coordination. This supramolecular cross-linked elastomer not only exhibits remarkable mechanical and conductive properties but also demonstrates stable and reliable signal response capabilities when used as a strain sensor. The elastomer possesses a tensile strength of 4.63 MPa and an elongation at break of 893%, with an electrical conductivity of up to 2.67 x 10-4 S<middle dot>m-1. Moreover, it achieves a healing efficiency exceeding 90% when subjected to 80 degrees C for healing for 24 h. Additionally, the elastomer-based strain sensor is capable of sensitively detecting human joint motion, underscoring its potential for applications in the realm of flexible wearable devices and health monitoring.