Facile “Synergistic Inner–Outer Activation” Strategy for Nano‐Engineering of Nature‐Skin–Derived Wearable Daytime Radiation Cooling Materials

Abstract

Natural skin–derived products, as traditional wearable materials are widely used in people's daily life due to the products’ excellent origins. Herein, a versatile daytime‐radiation cooling wearable natural skin (RC‐skin) consisting of the collagen micro‐nano fibers with the on‐demand double‐layer radiation cooling structure is nano‐engineered through the proposed facile “synergistic inner–outer activation” strategy. The bottom layer (inner strategy) of the RC‐skin is fabricated by filling the skin with the Mg11(HPO3)8(OH)6 nanoparticles by soaking. The superstratum (outer strategy) is constituted by a composite coating with an irregular microporous structure. The RC‐skin harvests the inherent advantages of natural building blocks including sufficient hydrophobicity, excellent mechanical properties, and friction resistance. Owing to the subtle double‐layer structure design, the solar reflectance and the average emissivity in the mid‐infrared band of RC‐skin are ≈92.7% and ≈95%, respectively. Therefore, the RC‐skin's temperature in the sub‐ambient is reduced by ≈7.5 °C. Various outdoor practical application experiments further substantiate that RC‐skin has superior radiation cooling performances. Collectively, RC‐skin has broad‐application prospects for intelligent wearing, low‐carbon travel, building materials, and intelligent thermoelectric power generation, and this study also provides novel strategies for developing natural‐skin–derived functional materials.

From natural leather to intelligent wearable nanocomposite: design and application

“…Recently, many studies have reported the development of multifunctional textiles for intelligent thermoregulation, which could maintain human body temperature in a comfortable area [76] . Most animal fur benefits from the low thermal conductivity brought by their multilayer and porous skin structure; thus, they can effectively reduce heat loss and have a natural insulation effect [37] .…”

Nano-engineered versatile Janus natural-skin with sandwich structure for wearable all-season personal thermal management

“…2b, with speci c structural formulas of Mg 11 (HPO 3 ) 8 (OH) 6 detailed in a previous study. [31] As the SHRC-skin has distinct coatings on its two sides, its RC-side and SH-side were characterized separately using FT-IR spectroscopy, as depicted in Fig. 2c.…”

“…[25][26][27][28][29] Building on this progress, researchers have devised various wearable fabrics for thermal management. [30][31][32][33] However, to our knowledge, most wearable fabrics with thermal management features typically offer only a heating or cooling function, which cannot effectively adapt to dynamic seasonal and weather changes. Moreover, this one-dimensional thermal management performance signi cantly limits the applicability of wearable fabrics.…”

“…[37][38][39][40] These qualities have made natural-skin a preferred substrate for the creation of wearable fabrics, and, more recently, a handful of functional natural-skin materials with thermal management properties have been successfully developed. [31,41,42] However, existing naturalskin products with single thermal management attributes fall short in addressing seasonal and weather changes. In extreme temperatures, passive radiative cooling or solar heating based on natural-skin can have counterproductive effects, resulting in accelerated aging, cracking, fading, or reduced exibility.…”

“…In extreme temperatures, passive radiative cooling or solar heating based on natural-skin can have counterproductive effects, resulting in accelerated aging, cracking, fading, or reduced exibility. [31] Additionally, the relatively simple thermal management capabilities of natural-skin no longer meet the demands of modern life with its diverse activities. Consequently, there remains a signi cant challenge in designing and producing a wearable natural-skin material that can adapt to temperature variations while offering comprehensive auxiliary functions like ammability resistance, electromagnetic interference (EMI) shielding, and physiological signal monitoring for cutting-edge applications, such as re ghting protective clothing, EMI shielding specialty garments, and telehealth monitoring.…”