Percolation threshold-inspired design of hierarchical multiscale hybrid architectures based on carbon nanotubes and silver nanoparticles for stretchable and printable electronics

Abstract

Conductive elastomers, an irreplaceable component of stretchable electronics, have recently gained significant attention. Herein, we report highly conductive, sensitive, stretchable, and fully printed hybrid composites comprising carbon nanotubes (CNTs), silver nanoparticles (Ag NPs) and hydroxyl-poly(styrene-block-butadiene-block-styrene) (OH-SBS) polymers. The electrically conductive composites are fabricated via direct evaporation of CNT-dispersed OH-SBS suspension under mild heating conditions, followed via an iterative process of silver precursor absorption and reduction, generating large amounts of Ag NPs on both the surface and inner regions of the CNT-embedded composites. The obtained CNT–Ag NP embedded composites possess a superior electrical conductivity of 1228 S cm⁻¹, a high break elongation of 540%, and a high gauge factor of 26 500. The unique hierarchical multiscale hybrid architecture of CNT–Ag NPs and the utilization of OH-SBS enable the as-prepared composites to exhibit huge piezoresistive behavior with a broad range of tensile strains. Moreover, handwritten electric circuits with diverse geometries are designed, and the printed strain gauge sensor could successfully detect sign language via its strain-sensing behavior. We believe that our hierarchical multiscale hybrid design could pave the way for the simple fabrication of stretchable circuits for wearable electronics.