Coassembly of elastomeric microfibers and silver nanowires for fabricating ultra-stretchable microtextiles with weakly and tunable negative permittivity

Abstract

In this work, a type of unique flexible and ultra-stretchable microtextiles was fabricated by coassembly of Ag nanowires (AgNWs) and thermoplastic polyurethane (TPU) microfibers. The microtexiles show tunable and weakly negative permittivity at a low filler content of 1.0–2.4 wt%. The resonance-induced negative permittivity observed in the AgNW/TPU microtextiles below the percolation threshold (fc) is attributed to the electric dipole moment of the isolated AgNWs, and this phenomenon can be explained by the Lorentz model. When the AgNW content exceeds the fc, the low-frequency collective plasma oscillation of the AgNW networks in the composites triggers the tunable plasma-type negative permittivity, which agrees with the Drude model. Additionally, the inductive character of the composites was assessed with the reactance spectra. The as-prepared Ag/TPU microtextiles could be a good candidate for the applications of garment integrated electronic, novel sensors, electromagnetic cloaking, and wearable electronic devices.