Thermally insulating mats based on electrospun fibers with bioinspired nano-groove surface structure

Heating and heat retention in buildings account for over 50 % of total energy costs, emphasizing the urgent need not only for advanced thermal insulation materials but also for nature-inspired design strategies to enhance energy efficiency and address the global energy crisis. In this study, we present a one-step fabrication method that improves both thermal insulation efficiency and the mechanical performance of polymer fiber mats. By leveraging bioinspired design, we successfully fabricate nanogroove fibers by precisely controlling humidity during in-situ electrospinning. This approach mimics the nanogroove topography of Old Man Cactus hair, enabling a simple yet effective method to regulate the nanoscale morphology of fibers. The resulting nanogroove fibers exhibit a substantial ~10 % reduction in surface temperature compared to conventional insulation coatings when applied to hot water pipes. Remarkably, our nanogroove fibrous coatings achieve 25 % higher energy savings per unit area and approximately 29 times higher per gram of material mass than commercial rubber insulation materials. This study highlights the critical role of nanoscale surface morphology engineering, particularly in the facile fabrication of nanogroove structures, in mitigating energy and heat loss during thermal transport processes. Based on the unique advantages of humidity-controlled polymer fiber architectures, this approach enables the development of flexible, high-performance thermal insulation materials, opening new avenues for versatile applications across various fields. • Fiber design is inspired by the nanogroove structure of Old Man Cactus hair. • Nanogroove fibers show ~10% lower surface temperature vs. conventional insulation coatings. • Coatings save 25% more energy per area and are ~29× more efficient by weight than rubber insulation. • Nanoscale surface morphology significantly improves thermal insulation performance. • The method enables scalable production of next-gen energy-saving insulation materials.