Twisted microropes for stretchable devices based on electrospun conducting polymer fibers doped with ionic liquid

Abstract

We report an effective method to fabricate poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)–polyvinyl pyrrolidone (PEDOT:PSS–PVP) fiber arrays doped with ionic liquid (IL). The twisted microropes were obtained by twisting the electrospun aligned polymer fiber arrays. It was found that the twisted rope exhibited higher electrical conductivity (∼1.8 × 10⁻⁴ S cm⁻¹) after IL doping (1.96 wt%) than those without doping (∼0.8 × 10⁻⁵ S cm⁻¹), and its conductivity was linearly correlated with strain up to 35% (which is one magnitude larger than previous reports) and showed repeatable cycle loops of tensile-resilience. The extensible rate could reach up to more than 90%, considerably higher than that of ropes without IL doping (∼17%). The results indicate that the twisted PEDOT:PSS–PVP ropes may be used as elastic semiconductors and stretchable sensors.