The sustainable development of strain sensors necessitates the use of mechanically robust and self-healing elastomers derived from biobased feedstocks to ensure durability, extend service life, and reduce reliance on fossil resources. Herein, we report mussel-inspired, fully biobased, mechanically robust, room-temperature healable supramolecular elastomer composites (SECs) fabricated from natural rubber (NR), polydopamine (PDA), and cellulose nanofiber (CNF). Hydrogen bonds were formed among the hydroxyl and secondary amine groups of PDA, hydroxyl groups of CNF, and the non-rubber components of NR, resulting in room-temperature self-healing and mechanically reinforced NR/PDA/CNF SECs. The SECs achieved a tensile strength of up to 9.5 MPa and recovered over 80 % of its strength after self-healing at room temperature for 3 h. The robust adhesion properties of PDA within the SECs enabled the surface coating of the SECs with conductive carbon nanotubes (CNT) to fabricate flexible strain sensors without additional adhesives through a simple dip-coating technique. These flexible strain sensors exhibited excellent structural stability, high sensitivity, and reliability, making them suitable for human motion signal detection. This study underscores the potential of biobased and self-healing elastomers in enhancing the performance and sustainability of flexible strain sensors, contributing significantly to the development of sustainable and durable sensing technologies.
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