Bioinspired Design of Strong, Tough, and Room-Temperature Healable Silicone Elastomers by Dynamic Nanoconfinement

Self-healing silicone elastomers are desirable matrix materials for electronic skin and wearable flexible electronics. However, the trade-off among strength, toughness, and self-healing performance remains a long-standing challenge owing to their inherent contradictions. Herein, bioinspired by spider silk, a dynamic nanoconfinement strategy was proposed to simultaneously achieve excellent strength, toughness, and self-healing performance in hydrogen-bonded silicone elastomers. A nanoconfined structure was constructed via precise regulation of a hydrogen-bonded state and phase-separated behavior using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The competitive interactions between Li + /TFSI – ions and urea moieties induced an order-to-disorder transition of hydrogen bonds, and the steric hindrance of TFSI – anions further inhibited excessive stacking of hard segments. This well-engineered structure with small and uniformly dispersed hard domains ensured high-molecular-chain mobility and suppressed stress concentration in the silicone elastomer, endowing it with high transparency (92.1%), skin-like Young’s modulus (1.5 MPa), high tensile strength (5.1 MPa), excellent toughness (33.6 MJ m –3 ), and outstanding room-temperature self-healing efficiency (97.0%). Moreover, the elastomers were successfully demonstrated for applications in strain sensing and recyclable transient circuits. This study offers a novel approach to developing robust, tough, and room-temperature self-healing elastomers, which holds broad prospects for applications in green and intelligent wearable electronic devices.