Construction of Mechanical Robust Elastomers by Simulating the Strengthening and Healing Process of Natural Skin toward Multifunctional Electronics

High-strength elastomers capable of room-temperature healing hold promising applications in flexible electronics. However, the unwanted spontaneous merging for the incorrect contact (such as folding or stacking) during the use process will prevent the widespread promotion of these elastomers. By simulating the strengthening and healing processes of natural skin, a series of robust and kinetically stable poly(urea-urethane) elastomers (PUU) were synthesized by integrating three reversible interactions, including dynamic disulfide bonds, hierarchical hydrogen bonds, and strain-induced crystallization, into polymer chains. Among these elastomers, PUU-DTDA9 exhibits high strength (40 MPa), exceptional transient room-temperature self-healing ability (97.71% healing efficiency of tensile strength), and good kinetic stability (no merging occurs at the contact area after it is kept at room temperature for 24 h). The exchangeability of disulfide bonds was locked by the hydrogen bonds with moderate density in the polymer chains, ensuring a high kinetic stability of the elastomer under service conditions. This prevents undesired merging efficiently while gaining an excellent transient self-healing ability triggered by ethanol at room temperature. Furthermore, to simulate the ion transport capabilities of natural skin, PUU-DTDA9 was mixed with ionic liquid to prepare sensitive multifunctional ionic skin with high tensile strength (18 MPa) and excellent transient self-healing ability, showing promising potential in high-performance flexible wearable electronics.