A personal thermal camouflage material based on nanofibrous polyamide membrane

Abstract

Developments in infrared (IR) sensing technology entail thermal camouflage to protect human body from an increased risk of detection. Despite explorations of various IR stealth techniques, achieving personal thermal camouflage with wearability remains a challenge. In this study, we propose a composite membrane consisting of electrospun nanofibrous polyamide-66 (PA66) backed with aluminum (Al) metallized nanoporous polyethylene (nanoPE) to achieve personal thermal camouflage. Our design promises body signature concealment in both detection bands (3–5 μm and 8–14 μm), and surface heat buildup is mitigated simultaneously via intrinsic absorption of PA66 (ɛ5–8 μm = 0.55), resulting in a consistently lower equilibrium temperature compared to non-spectrally-selective contrast samples. With an averaged solar reflectance exceeding 90 %, the skin-simulator temperature decreases over 20 °C compared to the uncovered state at peak solar intensity. Notably, the fabricated purely white PA66/Al/nanoPE strongly scatters ultraviolet light, making it feasible for multiband-compatible camouflage in snowy scenarios during winter. The wearability such as moisture penetrability (0.033 g·cm−2·h−1) and low air permeability are also assessed. With its camouflage performance, moisture permeability, windproofness and ease of preparation, this nanofibrous PA66/Al/nanoPE offers a promising solution for personal thermal camouflage applications and advances the field of functional garments for the future.