Recently, stretchable electronics have been highly desirable in the Internet of Things and electronic skins. Herein, an innovative and cost-efficient strategy is demonstrated to fabricate highly sensitive, stretchable, and conductive strain-sensing platforms inspired by the geometries of a spiders slit organ and a lobsters shell. The electrically conductive composites are fabricated via embedding the 3D percolation networks of fragmentized graphene sponges (FGS) in poly(styrene-block-butadiene-block-styrene) (SBS) matrix, followed by an iterative process of silver precursor absorption and reduction. The slit- and scale-like structures and hybrid conductive blocks of FGS and Ag nanoparticles (NPs) provide the obtained FGS-Ag-NP-embedded composites with superior electrical conductivity of 1521 S cm , high break elongation of 680%, a wide sensing range of up to 120% strain, high sensitivity of ≈10 at a strain of 120%, fast response time of ≈20 ms, as well as excellent reliability and stability of 2000 cycles. This huge stretchability and sensitivity is attributed to the combination of high stretchability of SBS and the binary synergistic effects of designed FGS architectures and Ag NPs. Moreover, the FGS/SBS/Ag composites can be employed as wearable sensors to detect the modes of finger motions successfully, and patterned conductive interconnects for flexible arrays of light-emitting diodes.

Covalently bonded graphene oxide/polyurethane composites with significant mechanical reinforcement and thermally healable capability were developed via in situ polymerization based on Diels–Alder chemistry.

The modified novolac epoxy resins with furan pendant groups were prepared by novolac epoxy resin and furfuryl alcohol and then crosslinked by bifunctional maleimide via Diels-Alder (DA) chemistry to obtain the thermally reversible and self-healing novolac epoxy resins. The as-prepared crosslinked novolac epoxy resins were characterized by FT-IR, NMR, TGA, and DMA. The results indicate that the novel crosslinked novolac epoxy resins present higher storage modulus (2.37 GPa at 30 C) and excellent thermal stability (348 C at 5% mass loss). Furthermore, the thermal reversible and self-healing properties were studied in detail by DSC, SEM, thermal re-solution, and gel-solution-gel transition experiments. All the results reveal that the crosslinked novolac epoxy resins based on DA reaction can be used as smart material for the practical application of electronic packaging and structural materials.