| 초록 |
The stretchable conductive fiber is one of the key components for human-friendly wearable electronic devices; they must be durable to withstand curvilinear deformation for practical use. The attempt to maximize both stretchability and conductivity, which is in a trade-off, is necessary to broaden the usage of stretchable conductive fiber. Herein, we presented a facile method to fabricate ultra-stretchable surface-enriched Ag nanoparticles (AgNPs) /polyurethane (PU) hybrid conductive fibers by modulating diffusion process with aqueous in-situ chemical reduction. To control diffusivity of Ag precursor, hydroxyl group solvents with varied molecular weights were used. The larger molecular weights have lower diffusivity, which enable to lead a clear local segregation between Ag NPs outer shell and PU core in the formation of AgNPs/PU hybrid conductive fiber. Due to stable electrical pathways in highly dense Ag rich shell, the fiber exhibits the highest conductivity (30,485 S cm-1) even at 300% tensile strain. The fibers were encapsulated by tough self-healing polymers (T-SHPs) to prevent propagation of Ag rich shell crack which is the dominant factor of weakening percolated AgNPs networks. The T-SHPs encapsulated stretchable conductive fibers showed enhanced conductivity about 4 times with solid stability for 1000 stretching cycles under 300% tensile strain. The T-SHPs encapsulated stretchable conductive fibers were applicated as self-bondable and self-weavable interconnects, showing new integration strategy for fiber-based devices. As a proof of concept, light emitting diode (LED) was stably turned on with the help of the T-SHPs encapsulated stretchable conductive fiber. Also, complex structure of textile wolf tattoo was fabricated using the self-bonding assembly. |
