Direct ink writing of silver nanowire-based flexible temperature sensors on fabric for wearable thermal monitoring

Abstract

We fabricate high-sensitivity flexible temperature sensors by direct ink writing of silver nanowires (AgNWs) on fabric. Optimized printing parameters (0.5 mm spacing, 6 layers) yield uniform conductivity (9.71 ± 0.21 Ω □⁻¹) with 130 °C sintering stabilization. The sensors exhibit 0.115–0.315% °C⁻¹ temperature coefficients and negligible hysteresis (ΔH(T) < 1.32) across −15–180 °C, enabled by phonon-boundary scattering in nanoscale networks. They demonstrate rapid response (7–102 s) constrained by textile thermal diffusivity, while photothermal conversion enables millisecond-resolution radiation detection (t₉₀ = 25.6 ± 0.1 s). Ambient tests confirm ±1.0 °C precision unaffected by humidity (20–80% RH) and airflow, with predictable compressive strain offsets (δT ≈ −2.1 °C at 10 kPa) and bending offsets (δT ≈ 2.5 °C at 33.33%). Validated in real-world scenarios including physiological motion monitoring (±2.0 °C stability), this textile-integrated platform overcomes flexibility-precision trade-offs for wearable healthcare and industrial sensing applications. This study addresses the limitations of AgNWs in temperature sensor applications, significantly advancing their practical implementation.