Penguin Feather-Biomimetic Thermal Insulation Materials Composed of Polyimide Nanofiber Aerogel and Windproof Membrane

Thermal insulation materials are essential for preserving human warmth in cold climates, and biomimetic strategies inspired by natural structures offer powerful design principles. Motivated by the feather architecture of penguins, which endure year-round temperatures of approximately −40°C to −60°C, a high-performance thermal-insulation (HPTI) material that reproduces the key features of feather structure by balancing thermal resistance, ultralow mass, and mechanical flexibility is reported. The HPTI is fabricated via a two-step electrospinning process with tailored spinning parameters to produce a hierarchical, feather-like architecture: a fluffy, air-holding polyimide (PI) nanofiber aerogel paired with a compact PI nanofiber windproof membrane, yielding an ultralow bulk density of 4.15 mg/cm 3 . Surface hydrophobicity is excellent, with water contact angles of 147° (aerogel) and 130° (windproof membrane). The assembled material with an areal density of 190 g/m 2 achieves a thermal-insulation ratio of 97.81%, a clothing insulation (clo) value of 6.518, and a heat-transfer coefficient of 0.72 W/K·m 2 . Combined with favorable compressibility and mechanical compliance, these characteristics make the HPTI a promising candidate for lightweight, flexible garments and protective systems intended for extreme-cold applications, while offering a scalable route to bioinspired thermal-management materials.